Drugs Details

Drugs Info of Valtrex
Drugs Details
  • Drugs Type  : Multum
  • Date : 20th Jun 2015 09:24 am
  • Brand Name : Valtrex
  • Generic Name : valacyclovir (Pronunciation: val a SYE kloe veer)
Descriptions

VALTREX (valacyclovir hydrochloride) is the hydrochloride salt of the L-valyl ester of the antiviral drug acyclovir.

VALTREX (valacyclovir hydrochloride) Caplets are for oral administration. Each caplet contains valacyclovir hydrochloride equivalent to 500 mg or 1 gram valacyclovir and the inactive ingredients carnauba wax, colloidal silicon dioxide, crospovidone, FD&C Blue No. 2 Lake, hypromellose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polysorbate 80, povidone, and titanium dioxide. The blue, film-coated caplets are printed with edible white ink.

The chemical name of valacyclovir hydrochloride is L-valine, 2-[(2-amino-1,6-dihydro-6oxo-9H-purin-9-yl)methoxy]ethyl ester, monohydrochloride. It has the following structural formula:

 

VALTREX (valacyclovir hydrochloride) Structural Formula Illustration

Valacyclovir hydrochloride is a white to off-white powder with the molecular formula C13H20N6O4•HCl and a molecular weight of 360.80. The maximum solubility in water at 25°C is 174 mg/mL. The pkas for valacyclovir hydrochloride are 1.90, 7.47, and 9.43.

What are the possible side effects of valacyclovir (Valtrex)?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop taking valacyclovir and call your doctor right away if you have any of the following signs of a serious side effect that can harm red blood cells:

  • fever, easy bruising or bleeding;
  • red spots on the skin (not related to herpes or chickenpox);
  • bloody diarrhea, vomiting;
  • pale or yellowed skin;
  • weakness or fainting; or
  • urinating less than usual or not at...

Read All Potential Side Effects and See Pictures of Valtrex »

What are the precautions when taking valacyclovir hydrochloride (Valtrex)?

See also Side Effects section.

Before taking valacyclovir, tell your doctor or pharmacist if you are allergic to it; or to acyclovir; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney problems.

This drug may rarely make you dizzy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Limit alcoholic beverages.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal...

Read All Potential Precautions of Valtrex »


This monograph has been modified to include the generic and brand name in many instances.

Indications

Adult Patients

Cold Sores (Herpes Labialis)

VALTREX® (valacyclovir hydrochloride) Caplets are indicated for treatment of cold sores (herpes labialis). The efficacy of VALTREX (valacyclovir hydrochloride) initiated after the development of clinical signs of a cold sore (e.g., papule, vesicle, or ulcer) has not been established.

Genital Herpes

Initial Episode: VALTREX (valacyclovir hydrochloride) is indicated for treatment of the initial episode of genital herpes in immunocompetent adults. The efficacy of treatment with VALTREX (valacyclovir hydrochloride) when initiated more than 72 hours after the onset of signs and symptoms has not been established.

Recurrent Episodes: VALTREX (valacyclovir hydrochloride) is indicated for treatment of recurrent episodes of genital herpes in immunocompetent adults. The efficacy of treatment with VALTREX (valacyclovir hydrochloride) when initiated more than 24 hours after the onset of signs and symptoms has not been established.

Suppressive Therapy: VALTREX (valacyclovir hydrochloride) is indicated for chronic suppressive therapy of recurrent episodes of genital herpes in immunocompetent and in HIV-infected adults. The efficacy and safety of VALTREX (valacyclovir hydrochloride) for the suppression of genital herpes beyond 1 year in immunocompetent patients and beyond 6 months in HIV-infected patients have not been established.

Reduction of Transmission: VALTREX (valacyclovir hydrochloride) is indicated for the reduction of transmission of genital herpes in immunocompetent adults. The efficacy of VALTREX (valacyclovir hydrochloride) for the reduction of transmission of genital herpes beyond 8 months in discordant couples has not been established. The efficacy of VALTREX (valacyclovir hydrochloride) for the reduction of transmission of genital herpes in individuals with multiple partners and non-heterosexual couples has not been established. Safer sex practices should be used with suppressive therapy (see current Centers for Disease Control and Prevention [CDC] Sexually Transmitted Diseases Treatment Guidelines).

Herpes Zoster

VALTREX (valacyclovir hydrochloride) is indicated for the treatment of herpes zoster (shingles) in immunocompetent adults. The efficacy of VALTREX (valacyclovir hydrochloride) when initiated more than 72 hours after the onset of rash and the efficacy and safety of VALTREX (valacyclovir hydrochloride) for treatment of disseminated herpes zoster have not been established.

Pediatric Patients

Cold Sores (Herpes Labialis)

VALTREX (valacyclovir hydrochloride) is indicated for the treatment of cold sores (herpes labialis) in pediatric patients ≥ 12 years of age. The efficacy of VALTREX (valacyclovir hydrochloride) initiated after the development of clinical signs of a cold sore (e.g., papule, vesicle, or ulcer) has not been established.

Chickenpox

VALTREX (valacyclovir hydrochloride) is indicated for the treatment of chickenpox in immunocompetent pediatric patients 2 to < 18 years of age. Based on efficacy data from clinical studies with oral acyclovir, treatment with VALTREX (valacyclovir hydrochloride) should be initiated within 24 hours after the onset of rash [see Clinical Studies].

Limitations of Use

The efficacy and safety of VALTREX (valacyclovir hydrochloride) have not been established in:

  • Immunocompromised patients other than for the suppression of genital herpes in HIV-infected patients with a CD4+ cell count ≥ 100 cells/mm³.
  • Patients < 12 years of age with cold sores (herpes labialis).
  • Patients < 2 years of age or ≥ 18 years of age with chickenpox.
  • Patients < 18 years of age with genital herpes.
  • Patients < 18 years of age with herpes zoster.
  • Neonates and infants as suppressive therapy following neonatal herpes simplex virus (HSV) infection.

Dosage Administration

  • VALTREX (valacyclovir hydrochloride) may be given without regard to meals.
  • Valacyclovir oral suspension (25 mg/mL or 50 mg/mL) may be prepared extemporaneously from 500 mg VALTREX (valacyclovir hydrochloride) Caplets for use in pediatric patients for whom a solid dosage form is not appropriate.

Adult Dosing Recommendations

Cold Sores (Herpes Labialis)

The recommended dosage of VALTREX (valacyclovir hydrochloride) for treatment of cold sores is 2 grams twice daily for 1 day taken 12 hours apart. Therapy should be initiated at the earliest symptom of a cold sore (e.g., tingling, itching, or burning).

Genital Herpes

Initial Episode: The recommended dosage of VALTREX (valacyclovir hydrochloride) for treatment of initial genital herpes is 1 gram twice daily for 10 days. Therapy was most effective when administered within 48 hours of the onset of signs and symptoms.

Recurrent Episodes: The recommended dosage of VALTREX (valacyclovir hydrochloride) for treatment of recurrent genital herpes is 500 mg twice daily for 3 days. Initiate treatment at the first sign or symptom of an episode.

Suppressive Therapy: The recommended dosage of VALTREX (valacyclovir hydrochloride) for chronic suppressive therapy of recurrent genital herpes is 1 gram once daily in patients with normal immune function. In patients with a history of 9 or fewer recurrences per year, an alternative dose is 500 mg once daily.

In HIV-infected patients with a CD4+ cell count ≥ 100 cells/mm³, the recommended dosage of VALTREX (valacyclovir hydrochloride) for chronic suppressive therapy of recurrent genital herpes is 500 mg twice daily.

Reduction of Transmission: The recommended dosage of VALTREX (valacyclovir hydrochloride) for reduction of transmission of genital herpes in patients with a history of 9 or fewer recurrences per year is 500 mg once daily for the source partner.

Herpes Zoster

The recommended dosage of VALTREX (valacyclovir hydrochloride) for treatment of herpes zoster is 1 gram 3 times daily for 7 days. Therapy should be initiated at the earliest sign or symptom of herpes zoster and is most effective when started within 48 hours of the onset of rash.

Pediatric Dosing Recommendations

Cold Sores (Herpes Labialis)

The recommended dosage of VALTREX (valacyclovir hydrochloride) for the treatment of cold sores in pediatric patients ≥ 12 years of age is 2 grams twice daily for 1 day taken 12 hours apart. Therapy should be initiated at the earliest symptom of a cold sore (e.g., tingling, itching, or burning).

Chickenpox

The recommended dosage of VALTREX (valacyclovir hydrochloride) for treatment of chickenpox in immunocompetent pediatric patients 2 to < 18 years of age is 20 mg/kg administered 3 times daily for 5 days. The total dose should not exceed 1 gram 3 times daily. Therapy should be initiated at the earliest sign or symptom [see Use in Specific Populations, CLINICAL PHARMACOLOGY, Clinical Studies].

Extemporaneous Preparation of Oral Suspension

Ingredients and Preparation per USP-NF

VALTREX (valacyclovir hydrochloride) Caplets 500 mg, cherry flavor, and Suspension Structured Vehicle USP-NF (SSV). Valacyclovir oral suspension (25 mg/mL or 50 mg/mL) should be prepared in lots of 100 mL.

Prepare Suspension at Time of Dispensing as Follows
  • Prepare SSV according to the USP-NF.
  • Using a pestle and mortar, grind the required number of VALTREX (valacyclovir hydrochloride) 500 mg Caplets until a fine powder is produced (5 VALTREX (valacyclovir hydrochloride) Caplets for 25 mg/mL suspension; 10 VALTREX (valacyclovir hydrochloride) Caplets for 50 mg/mL suspension).
  • Gradually add approximately 5 mL aliquots of SSV to the mortar and triturate the powder until a paste has been produced. Ensure that the powder has been adequately wetted.
  • Continue to add approximately 5 mL aliquots of SSV to the mortar, mixing thoroughly between additions, until a concentrated suspension is produced, to a minimum total quantity of 20 mL SSV and a maximum total quantity of 40 mL SSV for both the 25 mg/mL and 50 mg/mL suspensions.
  • Transfer the mixture to a suitable 100 mL measuring flask.
  • Transfer the cherry flavor* to the mortar and dissolve in approximately 5 mL of SSV. Once dissolved, add to the measuring flask.
  • Rinse the mortar at least 3 times with approximately 5 mL aliquots of SSV, transferring the rinsing to the measuring flask between additions.
  • Make the suspension to volume (100 mL) with SSV and shake thoroughly to mix.
  • Transfer the suspension to an amber glass medicine bottle with a child-resistant closure.
  • The prepared suspension should be labeled with the following information “Shake well before using. Store suspension between 2° to 8°C (36° to 46°F) in a refrigerator. Discard after 28 days.”

*The amount of cherry flavor added is as instructed by the suppliers of the cherry flavor.

Patients With Renal Impairment

Dosage recommendations for adult patients with reduced renal function are provided in Table 1 [see Use in Specific Populations, CLINICAL PHARMACOLOGY]. Data are not available for the use of VALTREX (valacyclovir hydrochloride) in pediatric patients with a creatinine clearance < 50 mL/min/1.73 m².

Table 1: VALTREX (valacyclovir hydrochloride) Dosage Recommendations for Adults With Renal Impairment

Indications Normal Dosage Regimen (Creatinine Clearance ≥ 50 mL/min) Creatinine Clearance (mL/min)
30-49 10-29 < 10
Cold sores (Herpes labialis) Two 2 gram doses taken Two 1 gram doses taken Two 500 mg doses taken 500 mg single dose
Do not exceed 1 day of treatment 12 hours apart 12 hours apart 12 hours apart  
Genital herpes: Initial episode 1 gram every 12 hours no reduction 1 gram every 24 hours 500 mg every 24 hours
Genital herpes: Recurrent episode 500 mg every 12 hours no reduction 500 mg every 24 hours 500 mg every 24 hours
Genital herpes: Suppressive therapy
  Immunocompetent patients 1 gram every 24 hours no reduction 500 mg every 24 hours 500 mg every 24 hours
  Alternate dose for immunocompetent patients with ≤ 9 recurrences/year 500 mg every 24 hours no reduction 500 mg every 48 hours 500 mg every 48 hours
  HIV-infected patients 500 mg every 12 hours no reduction 500 mg every 24 hours 500 mg every 24 hours
  Herpes zoster 1 gram every 8 hours 1 gram every 12 hours 1 gram every 24 hours 500 mg every 24 hours
Hemodialysis

Patients requiring hemodialysis should receive the recommended dose of VALTREX (valacyclovir hydrochloride) after hemodialysis. During hemodialysis, the half-life of acyclovir after administration of VALTREX (valacyclovir hydrochloride) is approximately 4 hours. About one third of acyclovir in the body is removed by dialysis during a 4-hour hemodialysis session.

Peritoneal Dialysis

There is no information specific to administration of VALTREX (valacyclovir hydrochloride) in patients receiving peritoneal dialysis. The effect of chronic ambulatory peritoneal dialysis (CAPD) and continuous arteriovenous hemofiltration/dialysis (CAVHD) on acyclovir pharmacokinetics has been studied. The removal of acyclovir after CAPD and CAVHD is less pronounced than with hemodialysis, and the pharmacokinetic parameters closely resemble those observed in patients with end-stage renal disease (ESRD) not receiving hemodialysis. Therefore, supplemental doses of VALTREX (valacyclovir hydrochloride) should not be required following CAPD or CAVHD.

How Supplied

Dosage Forms And Strengths

Caplets
  • 500 mg: blue, film-coated, capsule-shaped tablets printed with “VALTREX (valacyclovir hydrochloride) 500 mg.”
  • 1 gram: blue, film-coated, capsule-shaped tablets, with a partial scorebar on both sides, printed with “VALTREX (valacyclovir hydrochloride) 1 gram.”

Storage And Handling

VALTREX (valacyclovir hydrochloride) Caplets (blue, film-coated, capsule-shaped tablets) containing valacyclovir hydrochloride equivalent to 500 mg valacyclovir and printed with “VALTREX (valacyclovir hydrochloride) 500 mg.”

Bottle of 30 (NDC 0173-0933-08).
Bottle of 90 (NDC 0173-0933-10).
Unit dose pack of 100 (NDC 0173-0933-56).

VALTREX (valacyclovir hydrochloride) Caplets (blue, film-coated, capsule-shaped tablets, with a partial scorebar on both sides) containing valacyclovir hydrochloride equivalent to 1 gram valacyclovir and printed with “VALTREX (valacyclovir hydrochloride) 1 gram.”

Bottle of 30 (NDC 0173-0565-04).
Bottle of 90 (NDC 0173-0565-10).

Storage

Store at 15° to 25°C (59° to 77°F). Dispense in a well-closed container as defined in the USP.

Distributed by: GlaxoSmithKline Research Triangle Park, NC 27709. Manufactured by: GlaxoSmithKline Research Triangle Park, NC 27709 or DSM Pharmaceuticals, Inc. Greenville, NC 27834. March 2010


This monograph has been modified to include the generic and brand name in many instances.

Side Effects

The following serious adverse reactions are discussed in greater detail in other sections of the labeling:

  • Thrombotic Thrombocytopenic Purpura/Hemolytic Uremic Syndrome [see WARNINGS AND PRECAUTIONS].
  • Acute Renal Failure [seeWARNINGS AND PRECAUTIONS].
  • Central Nervous System Effects [seeWARNINGS AND PRECAUTIONS].

The most common adverse reactions reported in at least 1 indication by > 10% of adult patients treated with VALTREX (valacyclovir hydrochloride) and observed more frequently with VALTREX (valacyclovir hydrochloride) compared to placebo are headache, nausea, and abdominal pain. The only adverse reaction reported in > 10% of pediatric patients < 18 years of age was headache.

Clinical Trials Experience in Adult Patients

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in practice.

Cold Sores (Herpes Labialis)

In clinical studies for the treatment of cold sores, the adverse reactions reported by patients receiving VALTREX (valacyclovir hydrochloride) 2 grams twice daily (n = 609) or placebo (n = 609) for 1 day, respectively, included headache (14%, 10%) and dizziness (2%, 1%). The frequencies of abnormal ALT ( > 2 x ULN) were 1.8% for patients receiving VALTREX (valacyclovir hydrochloride) compared with 0.8% for placebo. Other laboratory abnormalities (hemoglobin, white blood cells, alkaline phosphatase, and serum creatinine) occurred with similar frequencies in the 2 groups.

Genital Herpes

Initial Episode: In a clinical study for the treatment of initial episodes of genital herpes, the adverse reactions reported by ≥ 5% of patients receiving VALTREX (valacyclovir hydrochloride) 1 gram twice daily for 10 days (n = 318) or oral acyclovir 200 mg 5 times daily for 10 days (n = 318), respectively, included headache (13%, 10%) and nausea (6%, 6%). For the incidence of laboratory abnormalities see Table 2.

Recurrent Episodes: In 3 clinical studies for the episodic treatment of recurrent genital herpes, the adverse reactions reported by ≥ 5% of patients receiving VALTREX (valacyclovir hydrochloride) 500 mg twice daily for 3 days (n = 402), VALTREX (valacyclovir hydrochloride) 500 mg twice daily for 5 days (n = 1,136) or placebo (n = 259), respectively, included headache (16%, 11%, 14%) and nausea (5%, 4%, 5%).

For the incidence of laboratory abnormalities see Table 2.

Suppressive Therapy: Suppression of Recurrent Genital Herpes in Immunocompetent Adults: In a clinical study for the suppression of recurrent genital herpes infections, the adverse reactions reported by patients receiving VALTREX (valacyclovir hydrochloride) 1 gram once daily (n = 269), VALTREX (valacyclovir hydrochloride) 500 mg once daily (n = 266), or placebo (n = 134), respectively, included headache (35%, 38%, 34%), nausea (11%, 11%, 8%), abdominal pain (11%, 9%, 6%), dysmenorrhea (8%, 5%, 4%), depression (7%, 5%, 5%), arthralgia (6%, 5%, 4%), vomiting (3%, 3%, 2%), and dizziness (4%, 2%, 1%). For the incidence of laboratory abnormalities see Table 2.

Suppression of Recurrent Genital Herpes in HIV-Infected Patients: In HIV-infected patients, frequently reported adverse reactions for VALTREX (valacyclovir hydrochloride) (500 mg twice daily; n = 194, median days on therapy = 172) and placebo (n = 99, median days on therapy = 59), respectively, included headache (13%, 8%), fatigue (8%, 5%), and rash (8%, 1%). Post-randomization laboratory abnormalities that were reported more frequently in valacyclovir subjects versus placebo included elevated alkaline phosphatase (4%, 2%), elevated ALT (14%, 10%), elevated AST (16%, 11%), decreased neutrophil counts (18%, 10%), and decreased platelet counts (3%, 0%), respectively.

Reduction of Transmission: In a clinical study for the reduction of transmission of genital herpes, the adverse reactions reported by patients receiving VALTREX (valacyclovir hydrochloride) 500 mg once daily (n = 743) or placebo once daily (n = 741), respectively, included headache (29%, 26%), nasopharyngitis (16%, 15%), and upper respiratory tract infection (9%, 10%).

Herpes Zoster

In 2 clinical studies for the treatment of herpes zoster, the adverse reactions reported by patients receiving VALTREX (valacyclovir hydrochloride) 1 gram 3 times daily for 7 to 14 days (n = 967) or placebo (n = 195), respectively, included nausea (15%, 8%), headache (14%, 12%), vomiting (6%, 3%), dizziness (3%, 2%), and abdominal pain (3%, 2%). For the incidence of laboratory abnormalities see Table 2.

Table 2: Incidence (%) of Laboratory Abnormalities in Herpes Zoster and Genital Herpes Study Populations

Laboratory Abnormality Herpes Zoster Genital Herpes Treatment Genital Herpes Suppression
VALTREX (valacyclovir hydrochloride)
1 gram
3 times daily
(n = 967)
Place­bo
(n = 195)
VALTREX (valacyclovir hydrochloride)
1 gram
twice daily
(n = 1,194)
VALTREX (valacyclovir hydrochloride)
500 mg
twice daily
(n = 1,159)
Place­bo
(n = 439)
VALTREX (valacyclovir hydrochloride)
1 gram
once daily
(n = 269)
VALTREX (valacyclovir hydrochloride)
500 mg
once daily
(n = 266)
Place­bo
(n = 134)
Hemoglobin ( < 0.8 x LLN) 0.8% 0% 0.3% 0.2% 0% 0% 0.8% 0.8%
White blood cells ( < 0.75 x LLN) 1.3% 0.6% 0.7% 0.6% 0.2% 0.7% 0.8% 1.5%
Platelet count ( < 100,000/mm³) 1.0% 1.2% 0.3% 0.1% 0.7% 0.4% 1.1% 1.5%
AST (SGOT) ( > 2 x ULN) 1.0% 0% 1.0% a 0.5% 4.1% 3.8% 3.0%
Serum creatinine ( > 1.5 x ULN) 0.2% 0% 0.7% 0% 0% 0% 0% 0%
a Data were not collected prospectively.
LLN = Lower limit of normal.
ULN = Upper limit of normal.

Clinical Trials Experience in Pediatric Patients

The safety profile of VALTREX (valacyclovir hydrochloride) has been studied in 177 pediatric patients 1 month to < 18 years of age. Sixty-five of these pediatric patients, 12 to < 18 years of age, received oral caplets for 1 to 2 days for treatment of cold sores. The remaining 112 pediatric patients, 1 month to < 12 years of age, participated in 3 pharmacokinetic and safety studies and received valacyclovir oral suspension. Fifty-one of these 112 pediatric patients received oral suspension for 3 to 6 days. The frequency, intensity, and nature of clinical adverse reactions and laboratory abnormalities were similar to those seen in adults.

Pediatric Patients 12 to < 18 Years of Age (Cold Sores)

In clinical studies for the treatment of cold sores, the adverse reactions reported by adolescent patients receiving VALTREX (valacyclovir hydrochloride) 2 grams twice daily for 1 day, or VALTREX (valacyclovir hydrochloride) 2 grams twice daily for 1 day followed by 1 gram twice daily for 1 day (n = 65, across both dosing groups), or placebo (n = 30), respectively, included headache (17%, 3%) and nausea (8%, 0%).

Pediatric Patients 1 Month to < 12 Years of Age

Adverse events reported in more than 1 subject across the 3 pharmacokinetic and safety studies in children 1 month to < 12 years of age were diarrhea (5%), pyrexia (4%), dehydration (2%), herpes simplex (2%), and rhinorrhea (2%). No clinically meaningful changes in laboratory values were observed.

Postmarketing Experience

In addition to adverse events reported from clinical trials, the following events have been identified during postmarketing use of VALTREX (valacyclovir hydrochloride) . Because they are reported voluntarily from a population of unknown size, estimates of frequency cannot be made. These events have been chosen for inclusion due to a combination of their seriousness, frequency of reporting, or potential causal connection to VALTREX (valacyclovir hydrochloride) .

General: Facial edema, hypertension, tachycardia.

Allergic: Acute hypersensitivity reactions including anaphylaxis, angioedema, dyspnea, pruritus, rash, and urticaria [see CONTRAINDICATIONS].

CNS Symptoms: Aggressive behavior; agitation; ataxia; coma; confusion; decreased consciousness; dysarthria; encephalopathy; mania; and psychosis, including auditory and visual hallucinations, seizures, tremors [see WARNINGS AND PRECAUTIONS, Use in Specific Populations].

Eye: Visual abnormalities.

Gastrointestinal: Diarrhea.

Hepatobiliary Tract and Pancreas: Liver enzyme abnormalities, hepatitis.

Renal: Renal failure, renal pain (may be associated with renal failure) [see WARNINGS AND PRECAUTIONS, Use in Specific Populations].

Hematologic: Thrombocytopenia, aplastic anemia, leukocytoclastic vasculitis, TTP/HUS [seeWARNINGS AND PRECAUTIONS].

Skin: Erythema multiforme, rashes including photosensitivity, alopecia.

Read the Valtrex (valacyclovir hydrochloride) Side Effects Center for a complete guide to possible side effects

Interactions

No clinically significant drug-drug or drug-food interactions with VALTREX are known [see CLINICAL PHARMACOLOGY].

Read the Valtrex Drug Interactions Center for a complete guide to possible interactions


This monograph has been modified to include the generic and brand name in many instances.

Warnings

Included as part of the PRECAUTIONS section.

Precautions

Thrombotic Thrombocytopenic Purpura/Hemolytic Uremic Syndrome (TTP/HUS)

TTP/HUS, in some cases resulting in death, has occurred in patients with advanced HIV disease and also in allogeneic bone marrow transplant and renal transplant recipients participating in clinical trials of VALTREX (valacyclovir hydrochloride) at doses of 8 grams per day. Treatment with VALTREX (valacyclovir hydrochloride) should be stopped immediately if clinical signs, symptoms, and laboratory abnormalities consistent with TTP/HUS occur.

Acute Renal Failure

Cases of acute renal failure have been reported in:

  • Elderly patients with or without reduced renal function. Caution should be exercised when administering VALTREX (valacyclovir hydrochloride) to geriatric patients, and dosage reduction is recommended for those with impaired renal function [see DOSAGE AND ADMINISTRATION, Use in Specific Populations].
  • Patients with underlying renal disease who received higher than recommended doses of VALTREX (valacyclovir hydrochloride) for their level of renal function. Dosage reduction is recommended when administering VALTREX to patients with renal impairment [see DOSAGE AND ADMINISTRATION, Use in Specific Populations].
  • Patients receiving other nephrotoxic drugs. Caution should be exercised when administering VALTREX (valacyclovir hydrochloride) to patients receiving potentially nephrotoxic drugs.
  • Patients without adequate hydration. Precipitation of acyclovir in renal tubules may occur when the solubility (2.5 mg/mL) is exceeded in the intratubular fluid. Adequate hydration should be maintained for all patients.

In the event of acute renal failure and anuria, the patient may benefit from hemodialysis until renal function is restored [see DOSAGE AND ADMINISTRATION, ADVERSE REACTIONS].

Central Nervous System Effects

Central nervous system adverse reactions, including agitation, hallucinations, confusion, delirium, seizures, and encephalopathy, have been reported in both adult and pediatric patients with or without reduced renal function and in patients with underlying renal disease who received higher than recommended doses of VALTREX (valacyclovir hydrochloride) for their level of renal function. Elderly patients are more likely to have central nervous system adverse reactions. VALTREX (valacyclovir hydrochloride) should be discontinued if central nervous system adverse reactions occur [see ADVERSE REACTIONS, Use in Specific Populations].

Patient Counseling Information

See FDA-Approved Patient Labeling.

Importance of Adequate Hydration

Patients should be advised to maintain adequate hydration.

Cold Sores (Herpes Labialis)

Patients should be advised to initiate treatment at the earliest symptom of a cold sore (e.g., tingling, itching, or burning). There are no data on the effectiveness of treatment initiated after the development of clinical signs of a cold sore (e.g., papule, vesicle, or ulcer). Patients should be instructed that treatment for cold sores should not exceed 1 day (2 doses) and that their doses should be taken about 12 hours apart. Patients should be informed that VALTREX (valacyclovir hydrochloride) is not a cure for cold sores.

Genital Herpes

Patients should be informed that VALTREX (valacyclovir hydrochloride) is not a cure for genital herpes. Because genital herpes is a sexually transmitted disease, patients should avoid contact with lesions or intercourse when lesions and/or symptoms are present to avoid infecting partners. Genital herpes is frequently transmitted in the absence of symptoms through asymptomatic viral shedding. Therefore, patients should be counseled to use safer sex practices in combination with suppressive therapy with VALTREX (valacyclovir hydrochloride) . Sex partners of infected persons should be advised that they might be infected even if they have no symptoms. Type-specific serologic testing of asymptomatic partners of persons with genital herpes can determine whether risk for HSV-2 acquisition exists.

VALTREX (valacyclovir hydrochloride) has not been shown to reduce transmission of sexually transmitted infections other than HSV-2.

If medical management of a genital herpes recurrence is indicated, patients should be advised to initiate therapy at the first sign or symptom of an episode.

There are no data on the effectiveness of treatment initiated more than 72 hours after the onset of signs and symptoms of a first episode of genital herpes or more than 24 hours after the onset of signs and symptoms of a recurrent episode.

There are no data on the safety or effectiveness of chronic suppressive therapy of more than 1 year's duration in otherwise healthy patients. There are no data on the safety or effectiveness of chronic suppressive therapy of more than 6 months' duration in HIV-infected patients.

Herpes Zoster

There are no data on treatment initiated more than 72 hours after onset of the zoster rash. Patients should be advised to initiate treatment as soon as possible after a diagnosis of herpes zoster.

Chickenpox

Patients should be advised to initiate treatment at the earliest sign or symptom of chickenpox.

This product's prescribing information may have been updated. Please refer to www.gsk.com for the most current version.

Nonclinical Toxicology

Carcinogenesis, Mutagenesis, Impairment of Fertility

The data presented below include references to the steady-state acyclovir AUC observed in humans treated with 1 gram VALTREX (valacyclovir hydrochloride) given orally 3 times a day to treat herpes zoster. Plasma drug concentrations in animal studies are expressed as multiples of human exposure to acyclovir [see CLINICAL PHARMACOLOGY].

Valacyclovir was noncarcinogenic in lifetime carcinogenicity bioassays at single daily doses (gavage) of valacyclovir giving plasma acyclovir concentrations equivalent to human levels in the mouse bioassay and 1.4 to 2.3 times human levels in the rat bioassay. There was no significant difference in the incidence of tumors between treated and control animals, nor did valacyclovir shorten the latency of tumors.

Valacyclovir was tested in 5 genetic toxicity assays. An Ames assay was negative in the absence or presence of metabolic activation. Also negative were an in vitro cytogenetic study with human lymphocytes and a rat cytogenetic study.

In the mouse lymphoma assay, valacyclovir was not mutagenic in the absence of metabolic activation. In the presence of metabolic activation (76% to 88% conversion to acyclovir), valacyclovir was mutagenic.

Valacyclovir was mutagenic in a mouse micronucleus assay.

Valacyclovir did not impair fertility or reproduction in rats at 6 times human plasma levels.

Use In Specific Populations

Pregnancy

Pregnancy Category B. There are no adequate and well-controlled studies of VALTREX (valacyclovir hydrochloride) or acyclovir in pregnant women. Based on prospective pregnancy registry data on 749 pregnancies, the overall rate of birth defects in infants exposed to acyclovir in-utero appears similar to the rate for infants in the general population. VALTREX (valacyclovir hydrochloride) should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

A prospective epidemiologic registry of acyclovir use during pregnancy was established in 1984 and completed in April 1999. There were 749 pregnancies followed in women exposed to systemic acyclovir during the first trimester of pregnancy resulting in 756 outcomes. The occurrence rate of birth defects approximates that found in the general population. However, the small size of the registry is insufficient to evaluate the risk for less common defects or to permit reliable or definitive conclusions regarding the safety of acyclovir in pregnant women and their developing fetuses.

Animal reproduction studies performed at oral doses that provided up to 10 and 7 times the human plasma levels during the period of major organogenesis in rats and rabbits, respectively, revealed no evidence of teratogenicity.

Nursing Mothers

Following oral administration of a 500 mg dose of VALTREX (valacyclovir hydrochloride) to 5 nursing mothers, peak acyclovir concentrations (Cmax) in breast milk ranged from 0.5 to 2.3 times (median 1.4) the corresponding maternal acyclovir serum concentrations. The acyclovir breast milk AUC ranged from 1.4 to 2.6 times (median 2.2) maternal serum AUC. A 500 mg maternal dosage of VALTREX (valacyclovir hydrochloride) twice daily would provide a nursing infant with an oral acyclovir dosage of approximately 0.6 mg/kg/day. This would result in less than 2% of the exposure obtained after administration of a standard neonatal dose of 30 mg/kg/day of intravenous acyclovir to the nursing infant. Unchanged valacyclovir was not detected in maternal serum, breast milk, or infant urine. Caution should be exercised when VALTREX (valacyclovir hydrochloride) is administered to a nursing woman.

Pediatric Use

VALTREX (valacyclovir hydrochloride) is indicated for treatment of cold sores in pediatric patients ≥ 12 years of age and for treatment of chickenpox in pediatric patients 2 to < 18 years of age [see INDICATIONS AND USAGE, DOSAGE AND ADMINISTRATION].

The use of VALTREX (valacyclovir hydrochloride) for treatment of cold sores is based on 2 double-blind, placebo-controlled clinical trials in healthy adults and adolescents ( ≥ 12 years of age) with a history of recurrent cold sores [see Clinical Studies].

The use of VALTREX (valacyclovir hydrochloride) for treatment of chickenpox in pediatric patients 2 to < 18 years of age is based on single-dose pharmacokinetic and multiple-dose safety data from an open-label trial with valacyclovir and supported by efficacy and safety data from 3 randomized, double-blind, placebo-controlled trials evaluating oral acyclovir in pediatric patients with chickenpox [see DOSAGE AND ADMINISTRATION, ADVERSE REACTIONS, CLINICAL PHARMACOLOGY, Clinical Studies].

The efficacy and safety of valacyclovir have not been established in pediatric patients:

  • < 12 years of age with cold sores
  • < 18 years of age with genital herpes
  • < 18 years of age with herpes zoster
  • < 2 years of age with chickenpox

for suppressive therapy following neonatal HSV infection.

The pharmacokinetic profile and safety of valacyclovir oral suspension in children < 12 years of age were studied in 3 open-label studies. No efficacy evaluations were conducted in any of the 3 studies.

Study 1 was a single-dose pharmacokinetic, multiple-dose safety study in 27 pediatric patients 1 to < 12 years of age with clinically suspected varicella-zoster virus (VZV) infection [see DOSAGE AND ADMINISTRATION, ADVERSE REACTIONS, CLINICAL PHARMACOLOGY, Clinical Studies].

Study 2 was a single-dose pharmacokinetic and safety study in pediatric patients 1 month to < 6 years of age who had an active herpes virus infection or who were at risk for herpes virus infection. Fifty-seven subjects were enrolled and received a single dose of 25 mg/kg valacyclovir oral suspension. In infants and children 3 months to < 6 years of age, this dose provided comparable systemic acyclovir exposures to that from a 1 gram dose of valacyclovir in adults (historical data). In infants 1 month to < 3 months of age, mean acyclovir exposures resulting from a 25 mg/kg dose were higher (Cmax: ↑30%, AUC: ↑60%) than acyclovir exposures following a 1 gram dose of valacyclovir in adults. Acyclovir is not approved for suppressive therapy in infants and children following neonatal HSV infections; therefore valacyclovir is not recommended for this indication because efficacy cannot be extrapolated from acyclovir.

Study 3 was a single-dose pharmacokinetic, multiple-dose safety study in 28 pediatric patients 1 to < 12 years of age with clinically suspected HSV infection. None of the children enrolled in this study had genital herpes. Each subject was dosed with valacyclovir oral suspension, 10 mg/kg twice daily for 3 to 5 days. Acyclovir systemic exposures in pediatric patients following valacyclovir oral suspension were compared with historical acyclovir systemic exposures in immunocompetent adults receiving the solid oral dosage form of valacyclovir or acyclovir for the treatment of recurrent genital herpes. The mean projected daily acyclovir systemic exposures in pediatric patients across all age-groups (1 to < 12 years of age) were lower (Cmax: ↓20%, AUC: ↓33%) compared with the acyclovir systemic exposures in adults receiving valacyclovir 500 mg twice daily, but were higher (daily AUC: ↑16%) than systemic exposures in adults receiving acyclovir 200 mg 5 times daily. Insufficient data are available to support valacyclovir for the treatment of recurrent genital herpes in this age-group because clinical information on recurrent genital herpes in young children is limited; therefore, extrapolating efficacy data from adults to this population is not possible. Moreover, valacyclovir has not been studied in children 1 to < 12 years of age with recurrent genital herpes.

Geriatric Use

Of the total number of subjects in clinical studies of VALTREX (valacyclovir hydrochloride) , 906 were 65 and over, and 352 were 75 and over. In a clinical study of herpes zoster, the duration of pain after healing (post-herpetic neuralgia) was longer in patients 65 and older compared with younger adults. Elderly patients are more likely to have reduced renal function and require dose reduction. Elderly patients are also more likely to have renal or CNS adverse events [see DOSAGE AND ADMINISTRATION, WARNINGS AND PRECAUTIONS, CLINICAL PHARMACOLOGY].

Renal Impairment

Dosage reduction is recommended when administering VALTREX (valacyclovir hydrochloride) to patients with renal impairment [see DOSAGE AND ADMINISTRATION, WARNINGS AND PRECAUTIONS].


This monograph has been modified to include the generic and brand name in many instances.

OverDose

Caution should be exercised to prevent inadvertent overdose [see Use in Specific Populations]. Precipitation of acyclovir in renal tubules may occur when the solubility (2.5 mg/mL) is exceeded in the intratubular fluid. In the event of acute renal failure and anuria, the patient may benefit from hemodialysis until renal function is restored [see DOSAGE AND ADMINISTRATION].

ContrainDications

VALTREX (valacyclovir hydrochloride) is contraindicated in patients who have had a demonstrated clinically significant hypersensitivity reaction (e.g., anaphylaxis) to valacyclovir, acyclovir, or any component of the formulation [see ADVERSE REACTIONS].


This monograph has been modified to include the generic and brand name in many instances.

Clinical Pharamacology

Mechanism of Action

Valacyclovir is an antiviral drug.

Pharmacokinetics

The pharmacokinetics of valacyclovir and acyclovir after oral administration of VALTREX (valacyclovir hydrochloride) have been investigated in 14 volunteer studies involving 283 adults and in 3 studies involving 112 pediatric subjects from 1 month to < 12 years of age.

Pharmacokinetics in Adults

Absorption and Bioavailability: After oral administration, valacyclovir hydrochloride is rapidly absorbed from the gastrointestinal tract and nearly completely converted to acyclovir and L-valine by first-pass intestinal and/or hepatic metabolism.

The absolute bioavailability of acyclovir after administration of VALTREX (valacyclovir hydrochloride) is 54.5% ± 9.1% as determined following a 1 gram oral dose of VALTREX (valacyclovir hydrochloride) and a 350 mg intravenous acyclovir dose to 12 healthy volunteers. Acyclovir bioavailability from the administration of VALTREX (valacyclovir hydrochloride) is not altered by administration with food (30 minutes after an 873 Kcal breakfast, which included 51 grams of fat).

Acyclovir pharmacokinetic parameter estimates following administration of VALTREX (valacyclovir hydrochloride) to healthy adult volunteers are presented in Table 3. There was a less than dose-proportional increase in acyclovir maximum concentration (Cmax) and area under the acyclovir concentration-time curve (AUC) after single-dose and multiple-dose administration (4 times daily) of VALTREX (valacyclovir hydrochloride) from doses between 250 mg to 1 gram.

There is no accumulation of acyclovir after the administration of valacyclovir at the recommended dosage regimens in adults with normal renal function.

Table 3: Mean (±SD) Plasma Acyclovir Pharmacokinetic Parameters Following Administration of VALTREX (valacyclovir hydrochloride) to Healthy Adult Volunteers

Dose Single-Dose Administration (N = 8) Multiple-Dose Administrationa
(N = 24, 8 per treatment arm)
Cmax (± SD)
(mcg/mL)
AUC (± SD)
(hr•mcg/mL)
Cmax (± SD)
(mcg/mL)
AUC (± SD)
(hr•mcg/mL)
100 mg 0.83 (± 0.14) 2.28 (± 0.40) ND ND
250 mg 2.15 (± 0.50) 5.76 (± 0.60) 2.11 (± 0.33) 5.66 (± 1.09)
500 mg 3.28 (± 0.83) 11.59 (± 1.79) 3.69 (± 0.87) 9.88 (± 2.01)
750 mg 4.17 (± 1.14) 14.11 (± 3.54) ND ND
1,000 mg 5.65 (± 2.37) 19.52 (± 6.04) 4.96 (± 0.64) 15.70 (± 2.27)
a Administered 4 times daily for 11 days.
ND = not done.
Distribution

The binding of valacyclovir to human plasma proteins ranges from 13.5% to 17.9%. The binding of acyclovir to human plasma proteins ranges from 9% to 33%.

Metabolism

Valacyclovir is converted to acyclovir and L-valine by first-pass intestinal and/or hepatic metabolism. Acyclovir is converted to a small extent to inactive metabolites by aldehyde oxidase and by alcohol and aldehyde dehydrogenase. Neither valacyclovir nor acyclovir is metabolized by cytochrome P450 enzymes. Plasma concentrations of unconverted valacyclovir are low and transient, generally becoming non-quantifiable by 3 hours after administration. Peak plasma valacyclovir concentrations are generally less than 0.5 mcg/mL at all doses. After single-dose administration of 1 gram of VALTREX (valacyclovir hydrochloride) , average plasma valacyclovir concentrations observed were 0.5, 0.4, and 0.8 mcg/mL in patients with hepatic dysfunction, renal insufficiency, and in healthy volunteers who received concomitant cimetidine and probenecid, respectively.

Elimination

The pharmacokinetic disposition of acyclovir delivered by valacyclovir is consistent with previous experience from intravenous and oral acyclovir. Following the oral administration of a single 1 gram dose of radiolabeled valacyclovir to 4 healthy subjects, 46% and 47% of administered radioactivity was recovered in urine and feces, respectively, over 96 hours. Acyclovir accounted for 89% of the radioactivity excreted in the urine. Renal clearance of acyclovir following the administration of a single 1 gram dose of VALTREX (valacyclovir hydrochloride) to 12 healthy volunteers was approximately 255 ± 86 mL/min which represents 42% of total acyclovir apparent plasma clearance.

The plasma elimination half-life of acyclovir typically averaged 2.5 to 3.3 hours in all studies of VALTREX (valacyclovir hydrochloride) in volunteers with normal renal function.

Specific Populations

Renal Impairment: Reduction in dosage is recommended in patients with renal impairment [see DOSAGE AND ADMINISTRATION, Use in Specific Populations].

Following administration of VALTREX (valacyclovir hydrochloride) to volunteers with ESRD, the average acyclovir half-life is approximately 14 hours. During hemodialysis, the acyclovir half-life is approximately 4 hours. Approximately one third of acyclovir in the body is removed by dialysis during a 4-hour hemodialysis session. Apparent plasma clearance of acyclovir in dialysis patients was 86.3 ± 21.3 mL/min/1.73 m² compared with 679.16 ± 162.76 mL/min/1.73 m² in healthy volunteers.

Hepatic Impairment: Administration of VALTREX (valacyclovir hydrochloride) to patients with moderate (biopsy-proven cirrhosis) or severe (with and without ascites and biopsy-proven cirrhosis) liver disease indicated that the rate but not the extent of conversion of valacyclovir to acyclovir is reduced, and the acyclovir half-life is not affected. Dosage modification is not recommended for patients with cirrhosis.

HIV Disease: In 9 patients with HIV disease and CD4+ cell counts < 150 cells/mm³ who received VALTREX (valacyclovir hydrochloride) at a dosage of 1 gram 4 times daily for 30 days, the pharmacokinetics of valacyclovir and acyclovir were not different from that observed in healthy volunteers.

Geriatrics: After single-dose administration of 1 gram of VALTREX (valacyclovir hydrochloride) in healthy geriatric volunteers, the half-life of acyclovir was 3.11 ± 0.51 hours, compared with 2.91 ± 0.63 hours in healthy younger adult volunteers. The pharmacokinetics of acyclovir following single- and multiple-dose oral administration of VALTREX (valacyclovir hydrochloride) in geriatric volunteers varied with renal function. Dose reduction may be required in geriatric patients, depending on the underlying renal status of the patient [see DOSAGE AND ADMINISTRATION, Use in Specific Populations].

Pediatrics: Acyclovir pharmacokinetics have been evaluated in a total of 98 pediatric patients (1 month to < 12 years of age) following administration of the first dose of an extemporaneous oral suspension of valacyclovir [see ADVERSE REACTIONS, Use in Specific Populations]. Acyclovir pharmacokinetic parameter estimates following a 20 mg/kg dose are provided in Table 4.

Table 4: Mean (±SD) Plasma Acyclovir Pharmacokinetic Parameter Estimates Following First-Dose Administration of 20 mg/kg Valacyclovir Oral Suspension to Pediatric Patients vs. 1 Gram Single Dose of VALTREX (valacyclovir hydrochloride) to Adults

Parameter Pediatric Patients (20mg/kg Oral Suspension) Adults1 gram
Solid Dose of
VALTREX (valacyclovir hydrochloride) a
(N = 15)
1 - < 2 yr
(N = 6)
2 - < 6 yr
(N = 12)
6 - < 12 yr
(N = 8)
AUC (mcg•hr/mL) 14.4 (±6.26) 10.1 (±3.35) 13.1 (±3.43) 17.2 (±3.10)
Cmax (mcg/mL) 4.03 (±1.37) 3.75 (±1.14) 4.71 (±1.20) 4.72 (±1.37)
a Historical estimates using pediatric pharmacokinetic sampling schedule.

Drug Interactions

When VALTREX (valacyclovir hydrochloride) is coadministered with antacids, cimetidine and/or probenicid, digoxin, or thiazide diuretics in patients with normal renal function, the effects are not considered to be of clinical significance (see below). Therefore, when VALTREX (valacyclovir hydrochloride) is coadministered with these drugs in patients with normal renal function, no dosage adjustment is recommended.

Antacids: The pharmacokinetics of acyclovir after a single dose of VALTREX (valacyclovir hydrochloride) (1 gram) were unchanged by coadministration of a single dose of antacids (Al3+ or Mg++).

Cimetidine: Acyclovir Cmax and AUC following a single dose of VALTREX (valacyclovir hydrochloride) (1 gram) increased by 8% and 32%, respectively, after a single dose of cimetidine (800 mg).

Cimetidine Plus Probenecid: Acyclovir Cmax and AUC following a single dose of VALTREX (valacyclovir hydrochloride) (1 gram) increased by 30% and 78%, respectively, after a combination of cimetidine and probenecid, primarily due to a reduction in renal clearance of acyclovir.

Digoxin: The pharmacokinetics of digoxin were not affected by coadministration of VALTREX (valacyclovir hydrochloride) 1 gram 3 times daily, and the pharmacokinetics of acyclovir after a single dose of VALTREX (valacyclovir hydrochloride) (1 gram) was unchanged by coadministration of digoxin (2 doses of 0.75 mg).

Probenecid: Acyclovir Cmax and AUC following a single dose of VALTREX (valacyclovir hydrochloride) (1 gram) increased by 22% and 49%, respectively, after probenecid (1 gram).

Thiazide Diuretics: The pharmacokinetics of acyclovir after a single dose of VALTREX (valacyclovir hydrochloride) (1 gram) were unchanged by coadministration of multiple doses of thiazide diuretics.

Microbiology

Mechanism of Action

Valacyclovir is a nucleoside analogue DNA polymerase inhibitor. Valacyclovir hydrochloride is rapidly converted to acyclovir which has demonstrated antiviral activity against HSV types 1 (HSV-1) and 2 (HSV-2) and VZV both in cell culture and in vivo.

The inhibitory activity of acyclovir is highly selective due to its affinity for the enzyme thymidine kinase (TK) encoded by HSV and VZV. This viral enzyme converts acyclovir into acyclovir monophosphate, a nucleotide analogue. The monophosphate is further converted into diphosphate by cellular guanylate kinase and into triphosphate by a number of cellular enzymes. In biochemical assays, acyclovir triphosphate inhibits replication of herpes viral DNA. This is accomplished in 3 ways: 1) competitive inhibition of viral DNA polymerase, 2) incorporation and termination of the growing viral DNA chain, and 3) inactivation of the viral DNA polymerase. The greater antiviral activity of acyclovir against HSV compared with VZV is due to its more efficient phosphorylation by the viral TK.

Antiviral Activities

The quantitative relationship between the cell culture susceptibility of herpesviruses to antivirals and the clinical response to therapy has not been established in humans, and virus sensitivity testing has not been standardized. Sensitivity testing results, expressed as the concentration of drug required to inhibit by 50% the growth of virus in cell culture (EC50), vary greatly depending upon a number of factors. Using plaque-reduction assays, the EC50 values against herpes simplex virus isolates range from 0.09 to 60 μM (0.02 to 13.5 mcg/mL) for HSV-1 and from 0.04 to 44 μM (0.01 to 9.9 mcg/mL) for HSV-2. The EC50 values for acyclovir against most laboratory strains and clinical isolates of VZV range from 0.53 to 48 μM (0.12 to 10.8 mcg/mL). Acyclovir also demonstrates activity against the Oka vaccine strain of VZV with a mean EC50 of 6 μM (1.35 mcg/mL).

Resistance

Resistance of HSV and VZV to acyclovir can result from qualitative and quantitative changes in the viral TK and/or DNA polymerase. Clinical isolates of VZV with reduced susceptibility to acyclovir have been recovered from patients with AIDS. In these cases, TK-deficient mutants of VZV have been recovered.

Resistance of HSV and VZV to acyclovir occurs by the same mechanisms. While most of the acyclovir-resistant mutants isolated thus far from immunocompromised patients have been found to be TK-deficient mutants, other mutants involving the viral TK gene (TK partial and TK altered) and DNA polymerase have also been isolated. TK-negative mutants may cause severe disease in immunocompromised patients. The possibility of viral resistance to valacyclovir (and therefore, to acyclovir) should be considered in patients who show poor clinical response during therapy.

Clinical Studies

Cold Sores (Herpes Labialis)

Two double-blind, placebo-controlled clinical trials were conducted in 1,856 healthy adults and adolescents ( ≥ 12 years old) with a history of recurrent cold sores. Patients self-initiated therapy at the earliest symptoms and prior to any signs of a cold sore. The majority of patients initiated treatment within 2 hours of onset of symptoms. Patients were randomized to VALTREX (valacyclovir hydrochloride) 2 grams twice daily on Day 1 followed by placebo on Day 2, VALTREX (valacyclovir hydrochloride) 2 grams twice daily on Day 1 followed by 1 gram twice daily on Day 2, or placebo on Days 1 and 2.

The mean duration of cold sore episodes was about 1 day shorter in treated subjects as compared with placebo. The 2 day regimen did not offer additional benefit over the 1-day regimen.

No significant difference was observed between subjects receiving VALTREX (valacyclovir hydrochloride) or placebo in the prevention of progression of cold sore lesions beyond the papular stage.

Genital Herpes Infections

Initial Episode

Six hundred forty-three immunocompetent adults with first-episode genital herpes who presented within 72 hours of symptom onset were randomized in a double-blind trial to receive 10 days of VALTREX (valacyclovir hydrochloride) 1 gram twice daily (n = 323) or oral acyclovir 200 mg 5 times a day (n = 320). For both treatment groups: the median time to lesion healing was 9 days, the median time to cessation of pain was 5 days, the median time to cessation of viral shedding was 3 days.

Recurrent Episodes

Three double-blind trials (2 of them placebo-controlled) in immunocompetent adults with recurrent genital herpes were conducted. Patients self-initiated therapy within 24 hours of the first sign or symptom of a recurrent genital herpes episode.

In 1 study, patients were randomized to receive 5 days of treatment with either VALTREX (valacyclovir hydrochloride) 500 mg twice daily (n = 360) or placebo (n = 259). The median time to lesion healing was 4 days in the group receiving VALTREX (valacyclovir hydrochloride) 500 mg versus 6 days in the placebo group, and the median time to cessation of viral shedding in patients with at least 1 positive culture (42% of the overall study population) was 2 days in the group receiving VALTREX (valacyclovir hydrochloride) 500 mg versus 4 days in the placebo group. The median time to cessation of pain was 3 days in the group receiving VALTREX (valacyclovir hydrochloride) 500 mg versus 4 days in the placebo group. Results supporting efficacy were replicated in a second trial.

In a third study, patients were randomized to receive VALTREX (valacyclovir hydrochloride) 500 mg twice daily for 5 days (n = 398) or VALTREX (valacyclovir hydrochloride) 500 mg twice daily for 3 days (and matching placebo twice daily for 2 additional days) (n = 402). The median time to lesion healing was about 4½ days in both treatment groups. The median time to cessation of pain was about 3 days in both treatment groups.

Suppressive Therapy

Two clinical studies were conducted, one in immunocompetent adults and one in HIV-infected adults.

A double-blind, 12-month, placebo- and active-controlled study enrolled immunocompetent adults with a history of 6 or more recurrences per year. Outcomes for the overall study population are shown in Table 5.

Table 5: Recurrence Rates in Immunocompetent Adults at 6 and 12 Months

View Enlarged Table

Subjects with 9 or fewer recurrences per year showed comparable results with VALTREX (valacyclovir hydrochloride) 500 mg once daily.

In a second study, 293 HIV-infected adults on stable antiretroviral therapy with a history of 4 or more recurrences of ano-genital herpes per year were randomized to receive either VALTREX (valacyclovir hydrochloride) 500 mg twice daily (n = 194) or matching placebo (n = 99) for 6 months. The median duration of recurrent genital herpes in enrolled subjects was 8 years, and the median number of recurrences in the year prior to enrollment was 5. Overall, the median prestudy HIV-1 RNA was 2.6 log10 copies/mL. Among patients who received VALTREX (valacyclovir hydrochloride) , the prestudy median CD4+ cell count was 336 cells/mm³; 11% had < 100 cells/mm³, 16% had 100 to 199 cells/mm³, 42% had 200 to 499 cells/mm³, and 31% had ≥ 500 cells/mm³. Outcomes for the overall study population are shown in Table 6.

Table 6: Recurrence Rates in HIV-Infected Adults at 6 Months

Outcome VALTREX (valacyclovir hydrochloride)
500 mg twice daily
(n = 194)
Placebo
(n = 99)
Recurrence free 65% 26%
Recurrences 17% 57%
Unknowna 18% 17%
a Includes lost to follow-up, discontinuations due to adverse events, and consent withdrawn.

Reduction of Transmission of Genital Herpes

A double-blind, placebo-controlled study to assess transmission of genital herpes was conducted in 1,484 monogamous, heterosexual, immunocompetent adult couples. The couples were discordant for HSV-2 infection. The source partner had a history of 9 or fewer genital herpes episodes per year. Both partners were counseled on safer sex practices and were advised to use condoms throughout the study period. Source partners were randomized to treatment with either VALTREX (valacyclovir hydrochloride) 500 mg once daily or placebo once daily for 8 months. The primary efficacy endpoint was symptomatic acquisition of HSV-2 in susceptible partners. Overall HSV-2 acquisition was defined as symptomatic HSV-2 acquisition and/or HSV-2 seroconversion in susceptible partners. The efficacy results are summarized in Table 7.

Table 7: Percentage of Susceptible Partners Who Acquired HSV-2 Defined by the Primary and Selected Secondary Endpoints

Endpoint VALTREXa
(n = 743)
Placebo
(n = 741)
Symptomatic HSV-2 acquisition 4 (0.5%) 16 (2.2%)
HSV-2 seroconversion 12 (1.6%) 24 (3.2%)
Overall HSV-2 acquisition 14 (1.9%) 27 (3.6%)
a Results show reductions in risk of 75% (symptomatic HSV-2 acquisition), 50% (HSV-2 seroconversion), and 48% (overall HSV-2 acquisition) with VALTREX versus placebo. Individual results may vary based on consistency of safer sex practices.

Herpes Zoster

Two randomized double-blind clinical trials in immunocompetent adults with localized herpes zoster were conducted. VALTREX (valacyclovir hydrochloride) was compared with placebo in patients less than 50 years of age, and with oral acyclovir in patients greater than 50 years of age. All patients were treated within 72 hours of appearance of zoster rash. In patients less than 50 years of age, the median time to cessation of new lesion formation was 2 days for those treated with VALTREX (valacyclovir hydrochloride) compared with 3 days for those treated with placebo. In patients greater than 50 years of age, the median time to cessation of new lesions was 3 days in patients treated with either VALTREX (valacyclovir hydrochloride) or oral acyclovir. In patients less than 50 years of age, no difference was found with respect to the duration of pain after healing (post-herpetic neuralgia) between the recipients of VALTREX (valacyclovir hydrochloride) and placebo. In patients greater than 50 years of age, among the 83% who reported pain after healing (post-herpetic neuralgia), the median duration of pain after healing [95% confidence interval] in days was: 40 [31, 51], 43 [36, 55], and 59 [41, 77] for 7-day VALTREX (valacyclovir hydrochloride) , 14-day VALTREX (valacyclovir hydrochloride) , and 7-day oral acyclovir, respectively.

Chickenpox

The use of VALTREX (valacyclovir hydrochloride) for treatment of chickenpox in pediatric patients 2 to < 18 years of age is based on single-dose pharmacokinetic and multiple-dose safety data from an open-label trial with valacyclovir and supported by safety and extrapolated efficacy data from 3 randomized, double-blind, placebo-controlled trials evaluating oral acyclovir in pediatric patients.

The single-dose pharmacokinetic and multiple-dose safety study enrolled 27 pediatric patients 1 to < 12 years of age with clinically suspected VZV infection. Each subject was dosed with valacyclovir oral suspension, 20 mg/kg 3 times daily for 5 days. Acyclovir systemic exposures in pediatric patients following valacyclovir oral suspension were compared with historical acyclovir systemic exposures in immunocompetent adults receiving the solid oral dosage form of valacyclovir or acyclovir for the treatment of herpes zoster. The mean projected daily acyclovir exposures in pediatric patients across all age-groups (1 to < 12 years of age) were lower (Cmax: ↓13%, AUC: ↓30%) than the mean daily historical exposures in adults receiving valacyclovir 1 gram 3 times daily, but were higher (daily AUC: ↑50%) than the mean daily historical exposures in adults receiving acyclovir 800 mg 5 times daily. The projected daily exposures in pediatric patients were greater (daily AUC approximately 100% greater) than the exposures seen in immunocompetent pediatric patients receiving acyclovir 20 mg/kg 4 times daily for the treatment of chickenpox. Based on the pharmacokinetic and safety data from this study and the safety and extrapolated efficacy data from the acyclovir studies, oral valacyclovir 20 mg/kg 3 times a day for 5 days (not to exceed 1 gram 3 times daily) is recommended for the treatment of chickenpox in pediatric patients 2 to < 18 years of age. Because the efficacy and safety of acyclovir for the treatment of chickenpox in children < 2 years of age have not been established, efficacy data cannot be extrapolated to support valacyclovir treatment in children < 2 years of age with chickenpox. Valacyclovir is also not recommended for the treatment of herpes zoster in children because safety data up to 7 days' duration are not available [see Use in Specific Populations].


This monograph has been modified to include the generic and brand name in many instances.

Patient Information

VALTREX®
(VAL-trex)
(valacyclovir hydrochloride) Caplets

Read the Patient Information that comes with VALTREX (valacyclovir hydrochloride) before you start using it and each time you get a refill. There may be new information. This information does not take the place of talking to your healthcare provider about your medical condition or treatment. Ask your healthcare provider or pharmacist if you have questions.

What is VALTREX (valacyclovir hydrochloride) ?

VALTREX (valacyclovir hydrochloride) is a prescription antiviral medicine. VALTREX (valacyclovir hydrochloride) lowers the ability of herpes viruses to multiply in your body.

VALTREX (valacyclovir hydrochloride) is used in adults:

  • to treat cold sores (also called fever blisters or herpes labialis)
  • to treat shingles (also called herpes zoster)
  • to treat or control genital herpes outbreaks in adults with normal immune systems
  • to control genital herpes outbreaks in adults infected with the human immunodeficiency virus (HIV) with CD4+ cell count greater than 100 cells/mm³
  • with safer sex practices to lower the chances of spreading genital herpes to others. Even with safer sex practices, it is still possible to spread genital herpes.

VALTREX (valacyclovir hydrochloride) used daily with the following safer sex practices can lower the chances of passing genital herpes to your partner.

  • Do not have sexual contact with your partner when you have any symptom or outbreak of genital herpes.
  • Use a condom made of latex or polyurethane whenever you have sexual contact.

VALTREX (valacyclovir hydrochloride) is used in children:

  • to treat cold sores (for children ≥ 12 years of age)
  • to treat chickenpox (for children 2 to < 18 years of age).

VALTREX (valacyclovir hydrochloride) does not cure herpes infections (cold sores, chickenpox, shingles, or genital herpes).

The efficacy of VALTREX (valacyclovir hydrochloride) has not been studied in children who have not reached puberty.

What are cold sores, chickenpox, shingles, and genital herpes?

Cold sores are caused by a herpes virus that may be spread by kissing or other physical contact with the infected area of the skin. They are small, painful ulcers that you get in or around your mouth. It is not known if VALTREX (valacyclovir hydrochloride) can stop the spread of cold sores to others.

Chickenpox is caused by a herpes virus. It causes an itchy rash of multiple small, red bumps that look like pimples or insect bites usually appearing first on the abdomen or back and face. It can spread to almost everywhere else on the body and may be accompanied by flu-like symptoms.

Shingles is caused by the same herpes virus that causes chickenpox. It causes small, painful blisters that happen on your skin. Shingles occurs in people who have already had chickenpox. Shingles can be spread to people who have not had chickenpox or the chickenpox vaccine by contact with the infected areas of the skin. It is not known if VALTREX (valacyclovir hydrochloride) can stop the spread of shingles to others.

Genital herpes is a sexually transmitted disease. It causes small, painful blisters on your genital area. You can spread genital herpes to others, even when you have no symptoms. If you are sexually active, you can still pass herpes to your partner, even if you are taking VALTREX (valacyclovir hydrochloride) .

VALTREX (valacyclovir hydrochloride) , taken every day as prescribed and used with the following safer sex practices, can lower the chances of passing genital herpes to your partner.

  • Do not have sexual contact with your partner when you have any symptom or outbreak of genital herpes.
  • Use a condom made of latex or polyurethane whenever you have sexual contact.

Ask your healthcare provider for more information about safer sex practices.

Who should not take VALTREX (valacyclovir hydrochloride) ?

Do not take VALTREX (valacyclovir hydrochloride) if you are allergic to any of its ingredients or to acyclovir. The active ingredient is valacyclovir. See the end of this leaflet for a complete list of ingredients in VALTREX (valacyclovir hydrochloride) .

Before taking VALTREX (valacyclovir hydrochloride) , tell your healthcare provider:

About all your medical conditions, including:

  • if you have had a bone marrow transplant or kidney transplant, or if you have advanced HIV disease or “AIDS”. Patients with these conditions may have a higher chance for getting a blood disorder called thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS). TTP/HUS can result in death.
  • if you have kidney problems. Patients with kidney problems may have a higher chance for getting side effects or more kidney problems with VALTREX (valacyclovir hydrochloride) . Your healthcare provider may give you a lower dose of VALTREX (valacyclovir hydrochloride) .
  • if you are 65 years of age or older. Elderly patients have a higher chance of certain side effects. Also, elderly patients are more likely to have kidney problems. Your healthcare provider may give you a lower dose of VALTREX (valacyclovir hydrochloride) .
  • if you are pregnant or planning to become pregnant. Talk with your healthcare provider about the risks and benefits of taking prescription drugs (including VALTREX (valacyclovir hydrochloride) ) during pregnancy.
  • if you are breastfeeding. VALTREX (valacyclovir hydrochloride) may pass into your milk and it may harm your baby. Talk with your healthcare provider about the best way to feed your baby if you are taking VALTREX (valacyclovir hydrochloride) .
  • about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements. VALTREX (valacyclovir hydrochloride) may affect other medicines, and other medicines may affect VALTREX (valacyclovir hydrochloride) . It is a good idea to keep a complete list of all the medicines you take. Show this list to your healthcare provider and pharmacist any time you get a new medicine.

How should I take VALTREX (valacyclovir hydrochloride) ?

Take VALTREX (valacyclovir hydrochloride) exactly as prescribed by your healthcare provider. Your dose of VALTREX (valacyclovir hydrochloride) and length of treatment will depend on the type of herpes infection that you have and any other medical problems that you have.

  • Do not stop VALTREX (valacyclovir hydrochloride) or change your treatment without talking to your healthcare provider.
  • VALTREX (valacyclovir hydrochloride) can be taken with or without food.
  • If you are taking VALTREX (valacyclovir hydrochloride) to treat cold sores, chickenpox, shingles, or genital herpes, you should start treatment as soon as possible after your symptoms start. VALTREX (valacyclovir hydrochloride) may not help you if you start treatment too late.
  • If you miss a dose of VALTREX (valacyclovir hydrochloride) , take it as soon as you remember and then take your next dose at its regular time. However, if it is almost time for your next dose, do not take the missed dose. Wait and take the next dose at the regular time.
  • Do not take more than the prescribed number of VALTREX (valacyclovir hydrochloride) Caplets each day. Call your healthcare provider right away if you take too much VALTREX (valacyclovir hydrochloride) .

What are the possible side effects of VALTREX (valacyclovir hydrochloride) ?

Kidney failure and nervous system problems are not common, but can be serious in some patients taking VALTREX (valacyclovir hydrochloride) . Nervous system problems include aggressive behavior, unsteady movement, shaky movements, confusion, speech problems, hallucinations (seeing or hearing things that are really not there), seizures, and coma. Kidney failure and nervous system problems have happened in patients who already have kidney disease and in elderly patients whose kidneys do not work well due to age. Always tell your healthcare provider if you have kidney problems before taking VALTREX (valacyclovir hydrochloride) . Call your doctor right away if you get a nervous system problem while you are taking VALTREX (valacyclovir hydrochloride) .

Common side effects of VALTREX (valacyclovir hydrochloride) in adults include headache, nausea, stomach pain, vomiting, and dizziness. Side effects in HIV-infected adults include headache, tiredness, and rash. These side effects usually are mild and do not cause patients to stop taking VALTREX (valacyclovir hydrochloride) .

Other less common side effects in adults include painful periods in women, joint pain, depression, low blood cell counts, and changes in tests that measure how well the liver and kidneys work.

The most common side effect seen in children < 18 years of age was headache.

Talk to your healthcare provider if you develop any side effects that concern you.

These are not all the side effects of VALTREX (valacyclovir hydrochloride) . For more information ask your healthcare provider or pharmacist.

How should I store VALTREX (valacyclovir hydrochloride) ?

  • Store VALTREX (valacyclovir hydrochloride) Caplets at room temperature, 59° to 77°F (15° to 25°C).
  • Store VALTREX (valacyclovir hydrochloride) suspension between 2° to 8°C (36° to 46°F) in a refrigerator. Discard after 28 days.
  • Keep VALTREX (valacyclovir hydrochloride) in a tightly closed container.
  • Do not keep medicine that is out of date or that you no longer need.
  • Keep VALTREX (valacyclovir hydrochloride) and all medicines out of the reach of children.

General information about VALTREX (valacyclovir hydrochloride)

Medicines are sometimes prescribed for conditions that are not mentioned in patient information leaflets. Do not use VALTREX (valacyclovir hydrochloride) for a condition for which it was not prescribed. Do not give VALTREX (valacyclovir hydrochloride) to other people, even if they have the same symptoms you have. It may harm them.

This leaflet summarizes the most important information about VALTREX (valacyclovir hydrochloride) . If you would like more information, talk with your healthcare provider. You can ask your healthcare provider or pharmacist for information about VALTREX (valacyclovir hydrochloride) that is written for health professionals. More information is available at www.VALTREX (valacyclovir hydrochloride) .com.

What are the ingredients in VALTREX?

Active Ingredient: valacyclovir hydrochloride

Inactive Ingredients: carnauba wax, colloidal silicon dioxide, crospovidone, FD&C Blue No. 2 Lake, hypromellose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polysorbate 80, povidone, and titanium dioxide.


This monograph has been modified to include the generic and brand name in many instances.

Consumer Overview Uses

IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.

 

VALACYCLOVIR - ORAL

 

(val-uh-SYE-klo-veer)

 

COMMON BRAND NAME(S): Valtrex

 

USES: Valacyclovir is used to treat infections caused by certain types of viruses. In children, it is used to treat cold sores around the mouth (caused by herpes simplex) and chickenpox (caused by varicella zoster). In adults, it is used to treat shingles (caused by herpes zoster) and cold sores around the mouth.

Valacyclovir is also used to treat outbreaks of genital herpes. In people with frequent outbreaks, this medication is used to reduce the number of future episodes.

Valacyclovir is an antiviral drug. It stops the growth of certain viruses. However, it is not a cure for these infections. The viruses that cause these infections continue to live in the body even between outbreaks. Valacyclovir decreases the severity and length of these outbreaks. It helps the sores heal faster, keeps new sores from forming, and decreases pain/itching. This medication may also help reduce how long pain remains after the sores heal.

 

OTHER USES: This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional.

This medication may also be used to prevent another type of viral infection (cytomegalovirus) in some people.

 

HOW TO USE: Read the Patient Information Leaflet if available from your pharmacist before you start taking valacyclovir and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

Take valacyclovir by mouth, with or without food, as directed by your doctor. Drink plenty of fluids while taking this medication to lower the chance of side effects.

The dosage and length of treatment are based on your type of infection, medical condition, and response to treatment. For treating chickenpox in children, the dosage is also based on weight.

This medication works best when started at the first sign of an outbreak, as directed by your doctor. It may not work as well if you delay treatment. For shingles or chickenpox, start taking valacyclovir at the first symptom or as soon as possible after the rash appears. For cold sores or genital herpes, start taking this medication at the first sign or as soon as you feel tingling, itching, or burning.

Valacyclovir works best when the amount of medicine in your body is kept at a constant level. Therefore, take this drug at evenly spaced intervals. To help you remember, take it at the same time(s) each day.

Continue to take this medication until the full prescribed amount is finished. Do not change your dose, skip any doses, or stop this medication early without your doctor's approval.

Tell your doctor if your condition persists or worsens.

Consumer Overview Side Effect

SIDE EFFECTS: Nausea, stomach pain, headache, or dizziness may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including: mental/mood changes (such as agitation, confusion, hallucinations), trouble speaking, shaky/unsteady movements, change in the amount of urine.

This medication may rarely cause a life-threatening disorder that affects the blood cells, kidneys, and other parts of the body. This disorder is more likely to occur if you have conditions related to a weakened immune system (such as HIV disease, bone marrow transplant, kidney transplant). Get medical help right away if you have any serious side effects, including: extreme tiredness, slow/fast/irregular heartbeat, easy bruising/bleeding, new fever, bloody/dark urine, severe stomach/abdominal pain, yellowing eyes/skin, sudden vision changes, loss of consciousness, seizures.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

 

Read the Valtrex (valacyclovir hydrochloride) Side Effects Center for a complete guide to possible side effects

Learn More »

PRECAUTIONS: See also Side Effects section.

Before taking valacyclovir, tell your doctor or pharmacist if you are allergic to it; or to acyclovir; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney problems.

This drug may rarely make you dizzy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Limit alcoholic beverages.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Do not have certain immunizations/vaccinations (such as vaccines against the varicella virus) without the consent of your doctor.

Older adults may be more sensitive to the side effects of this drug, especially mental/mood changes (such as confusion, agitation) and kidney problems (such as a change in the amount of urine).

Cold sores can spread easily. Avoid close physical contact with others (such as kissing) during an outbreak until the cold sores have completely healed. Try not to touch the cold sore. If you do, wash your hands afterward.

Valacyclovir does not prevent the spread of herpes. To lower the chance of giving genital herpes to your partner, do not have sexual contact during an outbreak or if you have symptoms. You can spread genital herpes even if you do not have symptoms. Therefore, always use an effective barrier method (latex or polyurethane condoms/dental dams) during all sexual activity. Consult your doctor or pharmacist for more details.

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

This medication passes into breast milk, but is unlikely to harm a nursing infant. Consult your doctor before breast-feeding.

Consumer Overview Missed Dose

DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Some products that may interact with this drug include: other drugs that may cause kidney problems (including nonsteroidal anti-inflammatory drugs-NSAIDs such as ibuprofen, naproxen).

Valacyclovir is very similar to acyclovir. Do not use medications containing acyclovir while using valacyclovir.

 

OVERDOSE: If overdose is suspected, contact a poison control center or emergency room immediately. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: change in the amount of urine, extreme tiredness, mental/mood changes, loss of consciousness, seizures.

 

NOTES: Do not share this medication with others.

This medication has been prescribed for your current condition only. Do not use it later for another infection unless your doctor directs you to do so. A different medication may be necessary in that case.

 

MISSED DOSE: If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

 

STORAGE: Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.

 

Information last revised October 2013. Copyright(c) 2013 First Databank, Inc.

Patient Detailed Side Effect

Brand Names: Valtrex

Generic Name: valacyclovir (Pronunciation: val a SYE kloe veer)

  • What is valacyclovir (Valtrex)?
  • What are the possible side effects of valacyclovir (Valtrex)?
  • What is the most important information I should know about valacyclovir (Valtrex)?
  • What should I discuss with my healthcare provider before taking valacyclovir (Valtrex)?
  • How should I take valacyclovir (Valtrex)?
  • What happens if I miss a dose (Valtrex)?
  • What happens if I overdose (Valtrex)?
  • What should I avoid while taking valacyclovir (Valtrex)?
  • What other drugs will affect valacyclovir (Valtrex)?
  • Where can I get more information?

What is valacyclovir (Valtrex)?

Valacyclovir is an antiviral drug. It slows the growth and spread of the herpes virus so that the body can fight off the infection. Valacyclovir will not cure herpes, but it can lessen the symptoms of the infection.

Valacyclovir is used to treat infections caused by herpes viruses in adults and children. Illnesses caused by herpes viruses include genital herpes, cold sores, shingles, and chickenpox.

Valacyclovir is used to treat cold sores in children who are at least 12 years old, and to treat chickenpox in children who are at least 2 years old.

Valacyclovir may also be used for other purposes not listed in this medication guide.

Valaciclovir 1 g-ROX

oval, white, imprinted with 54518

What are the possible side effects of valacyclovir (Valtrex)?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop taking valacyclovir and call your doctor right away if you have any of the following signs of a serious side effect that can harm red blood cells:

  • fever, easy bruising or bleeding;
  • red spots on the skin (not related to herpes or chickenpox);
  • bloody diarrhea, vomiting;
  • pale or yellowed skin;
  • weakness or fainting; or
  • urinating less than usual or not at all.

Call your doctor at once if you have any of these other serious side effects:

  • pain in your lower back;
  • drowsiness, mood changes, increased thirst, loss of appetite, nausea and vomiting;
  • swelling, weight gain, feeling short of breath;
  • confusion, agitation, aggression, hallucinations, trouble concentrating;
  • feeling shaky or unsteady;
  • problems with speech or vision; or
  • seizure (convulsions).

Less serious side effects may include:

  • nausea, stomach pain;
  • headache, dizziness, tired feeling, depression;
  • joint pain;
  • menstrual pain;
  • mild skin rash; or
  • stuffy nose, sore throat.

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect. You may report side effects to FDA at 1-800-FDA-1088.

Read the Valtrex (valacyclovir hydrochloride) Side Effects Center for a complete guide to possible side effects

Learn More »

What is the most important information I should know about valacyclovir (Valtrex)?

Before taking valacyclovir, tell your doctor if you have HIV/AIDS, a weak immune system, kidney disease (or if you are on dialysis), or if you have had a kidney or bone marrow transplant.

Valacyclovir can be harmful to the kidneys, and these effects are increased when it is used together with other medicines that can harm the kidneys. Tell your doctor about all other medications you are using. You may need dose adjustments or special tests when taking certain medications together with valacyclovir.

Treatment with valacyclovir should be started as soon as possible after the first appearance of symptoms (such as tingling, burning, blisters).

Herpes virus can be passed from an infected mother to her baby during childbirth. If you have genital herpes, it is very important to prevent herpes lesions during your pregnancy so that you do not have a genital lesion when your baby is born.

Valacyclovir will not prevent the spread of genital herpes. Herpes infections are contagious and you can infect other people even while you are taking with valacyclovir.

Stop taking valacyclovir and call your doctor right away if you have any signs of a serious side effect that can harm red blood cells, such as: fever, easy bruising or bleeding, red spots on the skin (not related to herpes or chickenpox), bloody diarrhea, vomiting, pale or yellowed skin, weakness, fainting, or urinating less than usual or not at all.

Do not give valacyclovir to a child unless it has been prescribed by a doctor.

Side Effects Centers
  • Valtrex

Patient Detailed How Take

What should I discuss with my healthcare provider before taking valacyclovir (Valtrex)?

Do not take this medicine if you are allergic to valacyclovir or acyclovir (Zovirax).

If you have certain conditions, you may need a dose adjustment or special tests to safely take this medication. Before taking valacyclovir, tell your doctor if you have:

  • HIV/AIDS, or other conditions that can weaken the immune system;
  • kidney disease (or if you are on dialysis); or
  • if you have had a kidney or bone marrow transplant.

FDA pregnancy category B. This medication is not expected to be harmful to an unborn baby. However, herpes virus can be passed from an infected mother to her baby during childbirth. If you have genital herpes, it is very important to prevent herpes lesions during your pregnancy so that you do not have a genital lesion when your baby is born.

Valacyclovir passes into breast milk and may harm a nursing infant. Do not take this medication without telling your doctor if you are breast-feeding a baby.

Do not give valacyclovir to a child unless it has been prescribed by a doctor.

Older adults may be more likely to have harmful side effects while taking valacyclovir. Talk to your doctor about your specific risk.

How should I take valacyclovir (Valtrex)?

Take this medication exactly as it was prescribed for you. Do not take the medication in larger amounts, or take it for longer than recommended by your doctor. Follow the directions on your prescription label.

Treatment with valacyclovir should be started as soon as possible after the first appearance of symptoms (such as tingling, burning, blisters). This medication might not be as effective if you first start taking it 1 or 2 days after the start of your symptoms.

Take each dose with a full glass of water. Drink plenty of water while you are taking valacyclovir to keep your kidneys working properly.

Shake the oral suspension (liquid) well just before you measure a dose. To be sure you get the correct dose, measure the liquid with a marked measuring spoon or medicine cup, not with a regular table spoon. If you do not have a dose-measuring device, ask your pharmacist for one.

Valacyclovir can be taken with or without food.

Take this medication for the entire length of time prescribed by your doctor. Your symptoms may get better before the infection is completely treated. Valacyclovir will not treat a viral infection such as the common cold or flu.

Lesions caused by herpes viruses should be kept as clean and dry as possible. Wearing loose clothing may help to prevent irritation of the lesions.

Store valacyclovir tablets at room temperature away from moisture and heat.

Store valacyclovir liquid in a refrigerator. Do not freeze. Throw away any unused valacyclovir that is older than 28 days.

Side Effects Centers
  • Valtrex

Patient Detailed Avoid Taking

What happens if I miss a dose (Valtrex)?

Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the medicine at the next regularly scheduled time. Do not take extra medicine to make up the missed dose.

What happens if I overdose (Valtrex)?

Seek emergency medical attention if you think you have used too much of this medicine.

Overdose symptoms may include urinating less than usual or not at all.

What should I avoid while taking valacyclovir (Valtrex)?

Valacyclovir will not prevent the spread of genital herpes. Herpes infections are contagious and you can infect other people even while you are taking with valacyclovir.

Avoid sexual intercourse or use a latex condom to prevent spreading the virus to others. Avoid letting infected areas come into contact with other people. Avoid touching an infected area and then touching your eyes. Wash your hands frequently to prevent passing the infection to others.

What other drugs will affect valacyclovir (Valtrex)?

Valacyclovir can be harmful to the kidneys, and these effects are increased when it is used together with other medicines that can harm the kidneys. Before taking valacyclovir, tell your doctor if you are also using:

  • lithium (Eskalith, Lithobid);
  • methotrexate (Rheumatrex, Trexal);
  • pain or arthritis medicines such as aspirin (Anacin, Excedrin), acetaminophen (Tylenol), diclofenac (Voltaren), etodolac (Lodine), ibuprofen (Advil, Motrin), indomethacin (Indocin), naproxen (Aleve, Naprosyn), and others;
  • medicines used to treat ulcerative colitis, such as mesalamine (Pentasa) or sulfasalazine (Azulfidine);
  • medicines used to prevent organ transplant rejection, such as sirolimus (Rapamune) or tacrolimus (Prograf);
  • IV antibiotics such as amphotericin B (Fungizone, AmBisome, Amphotec, Abelcet), amikacin (Amikin), bacitracin (Baci-IM), capreomycin (Capastat), gentamicin (Garamycin), kanamycin (Kantrex), streptomycin, or vancomycin (Vancocin, Vancoled);
  • antiviral medicines such as adefovir (Hepsera), cidofovir (Vistide), or foscarnet (Foscavir); or
  • cancer medicine such as aldesleukin (Proleukin), carmustine (BiCNU, Gliadel), cisplatin (Platinol), ifosfamide (Ifex), oxaliplatin (Eloxatin), plicamycin (Mithracin), streptozocin (Zanosar), or tretinoin (Vesanoid).

This list is not complete and there may be other drugs that can interact with valacyclovir. Tell your doctor about all your prescription and over-the-counter medications, vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start a new medication without telling your doctor.

Where can I get more information?

Your pharmacist can provide more information about valacyclovir.


Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2013 Cerner Multum, Inc. Version: 9.03. Revision date: 12/15/2010.

Your use of the content provided in this service indicates that you have read,understood and agree to the End-User License Agreement,which can be accessed by clicking on this link.

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