Drugs Details

Drugs Info of Tagamet, Tagamet HB
Drugs Details
  • Drugs Type  : Multum
  • Date : 16th Jun 2015 06:25 am
  • Brand Name : Tagamet, Tagamet HB
  • Generic Name : cimetidine (Pronunciation: sye ME ti deen)
Descriptions

Tagamet (cimetidine) is a histamine H2-receptor antagonist. Chemically it is N?-cyano-N-methyl N'-[2-[[(5-methyl-1H-imidazol-4-yl)methyl]thio]-ethyl]-guanidine.

The empirical formula for cimetidine is C10H16N6S and for cimetidine hydrochloride, C10H16N6SHCl; these represent molecular weights of 252.34 and 288.80, respectively.

Cimetidine contains an imidazole ring, and is chemically related to histamine.

(The liquid and injection dosage forms contain cimetidine as the hydrochloride.)

Cimetidine has a bitter taste and characteristic odor.

Solubility Characteristics : Cimetidine is soluble in alcohol, slightly soluble in water, very slightly soluble in chloroform and insoluble in ether. Cimetidine hydrochloride is freely soluble in water, soluble in alcohol, very slightly soluble in chloroform and practically insoluble in ether.

Tablets for Oral Administration : Each light green, film-coated tablet contains cimetidine as follows: 300 mg-round, debossed with the product name TAGAMET (cimetidine) , SB and 300; 400 mg-oval Tiltab® tablets, debossed with the product name TAGAMET (cimetidine) , SB and 400; 800 mg-oval Tiltab® tablets, debossed with the product name TAGAMET (cimetidine) , SB and 800. Inactive ingredients consist of cellulose, D&C Yellow No. 10, FD&C Blue No. 2, FD&C Red No. 40, FD&C Yellow No. 6, hydroxypropyl methylcellulose, iron oxides, magnesium stearate, povidone, propylene glycol, sodium lauryl sulfate, sodium starch glycolate, starch, titanium dioxide and trace amounts of other inactive ingredients.

Liquid for Oral Administration : Each 5 mL (1 teaspoonful) of clear, light orange, mint-peach flavored liquid contains cimetidine hydrochloride equivalent to cimetidine, 300 mg; alcohol, 2.8%. Inactive ingredients consist of FD&C Yellow No. 6, flavors, methylparaben, polyoxyethylene polyoxypropylene glycol, propylene glycol, propylparaben, saccharin sodium, sodium chloride, sodium phosphate, sorbitol and water.

Injection

Single-Dose Vials for Intramuscular or Intravenous Administration : Each 2 mL contains, in sterile aqueous solution (pH range 3.8 to 6), cimetidine hydrochloride equivalent to cimetidine, 300 mg; phenol, 10 mg.

Multi-Dose Vials for Intramuscular or Intravenous Administration : 8 mL (300 mg/2 mL): Each 2 mL contains, in sterile aqueous solution (pH range 3.8 to 6), cimetidine hydrochloride equivalent to cimetidine, 300 mg; phenol, 10 mg.

Single-Dose Premixed Plastic Containers for Intravenous Administration : Each 50 mL of sterile aqueous solution (pH range 5 to 7) contains cimetidine hydrochloride equivalent to 300 mg cimetidine and 0.45 grams sodium chloride.

No preservative has been added.

The plastic container is fabricated from specially formulated polyvinyl chloride. The amount of water that can permeate from inside the container into the overwrap is insufficient to affect the solution significantly. Solutions in contact with the plastic container can leach out certain of its chemical components in very small amounts within the expiration period, e.g., di 2-ethylhexyl phthalate (DEHP), up to 5 parts per million. However, the safety of the plastic has been confirmed in tests in animals according to the USP biological tests for plastic containers as well as by tissue culture toxicity studies.

ADD-Vantage®* Vials for Intravenous Administration : Each 2 mL contains, in sterile aqueous solution (pH range 3.8 to 6), cimetidine hydrochloride equivalent to cimetidine, 300 mg; phenol, 10 mg.

All of the above injection formulations are pyrogen free, and sodium hydroxide N.F. is used as an ingredient to adjust the pH.

*ADD-Vantage® is a trademark of Abbott Laboratories.

What are the possible side effects of cimetidine (Tagamet, Tagamet HB)?

Stop using cimetidine and 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.

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

  • cough, fever, chest congestion, trouble breathing;
  • red or blistering skin rash;
  • jaundice (yellowing of the skin or eyes);
  • easy bruising or bleeding, unusual weakness;
  • feeling faint, light-headed, disoriented, or confused;
  • urinating less than...

Read All Potential Side Effects and See Pictures of Tagamet »

What are the precautions when taking cimetidine (Tagamet)?

Before taking cimetidine, tell your doctor or pharmacist if you are allergic to it; or to other H2 blockers (e.g., famotidine, nizatidine, ranitidine); 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: immune system problems, kidney problems, liver problems, certain lung diseases (chronic obstructive pulmonary disease-COPD), diabetes, other stomach problems (e.g., tumors).

Some symptoms may actually be signs of a more serious condition. Get medical help right away if you have: heartburn with lightheadedness/sweating/dizziness, chest/jaw/arm/shoulder...

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

Indications

Tagamet (cimetidine) is indicated in:

(1) Short-term treatment of active duodenal ulcer. Most patients heal within 4 weeks and there is rarely reason to use Tagamet (cimetidine) at full dosage for longer than 6 to 8 weeks (see Dosage and Administration-Duodenal Ulcer). Concomitant antacids should be given as needed for relief of pain. However, simultaneous administration of Tagamet (cimetidine) and antacids is not recommended, since antacids have been reported to interfere with the absorption of Tagamet (cimetidine) .

(2) Maintenance therapy for duodenal ulcer patients at reduced dosage after healing of active ulcer. Patients have been maintained on continued treatment with Tagamet (cimetidine) 400 mg h.s. for periods of up to 5 years.

(3) Short-term treatment of active benign gastric ulcer. There is no information concerning usefulness of treatment periods of longer than 8 weeks.

(4) Erosive gastroesophageal reflux disease (GERD). Erosive esophagitis diagnosed by endoscopy. Treatment is indicated for 12 weeks for healing of lesions and control of symptoms. The use of Tagamet (cimetidine) beyond 12 weeks has not been established (see Dosage and Administration-GERD).

(5) Prevention of upper gastrointestinal bleeding in critically ill patients.

(6) The treatment of pathological hypersecretory conditions (i.e., Zollinger-Ellison Syndrome, systemic mastocytosis, multiple endocrine adenomas).

Dosage Administration

Duodenal Ulcer

Active Duodenal Ulcer: Clinical studies have indicated that suppression of nocturnal acid is the most important factor in duodenal ulcer healing (see Clinical Pharmacology-Acid Secretion). This is supported by recent clinical trials (see Clinical Trials-Active Duodenal Ulcer). Therefore, there is no apparent rationale, except for familiarity with use, for treating with anything other than a once-daily at bedtime dosage regimen (h.s.).

In a U.S. dose-ranging study of 400 mg h.s., 800 mg h.s. and 1600 mg h.s., a continuous dose response relationship for ulcer healing was demonstrated.

However, 800 mg h.s. is the dose of choice for most patients, as it provides a high healing rate (the difference between 800 mg h.s. and 1600 mg h.s. being small), maximal pain relief, a decreased potential for drug interactions (see Precautions-Drug Interactions) and maximal patient convenience. Patients unhealed at 4 weeks, or those with persistent symptoms, have been shown to benefit from 2 to 4 weeks of continued therapy.

It has been shown that patients who both have an endoscopically demonstrated ulcer larger than 1.0 cm and are also heavy smokers (i.e., smoke one pack of cigarettes or more per day) are more difficult to heal. There is some evidence which suggests that more rapid healing can be achieved in this subpopulation with Tagamet (cimetidine) 1600 mg at bedtime. While early pain relief with either 800 mg h.s. or 1600 mg h.s. is equivalent in all patients, 1600 mg h.s. provides an appropriate alternative when it is important to ensure healing within 4 weeks for this subpopulation. Alternatively, approximately 94% of all patients will also heal in 8 weeks with Tagamet (cimetidine) 800 mg h.s.

Other Tagamet (cimetidine) regimens in the U.S. which have been shown to be effective are: 300 mg four times daily, with meals and at bedtime, the original regimen with which U.S. physicians have the most experience, and 400 mg twice daily, in the morning and at bedtime (see Clinical Trials-Active Duodenal Ulcer).

Concomitant antacids should be given as needed for relief of pain. However, simultaneous administration of Tagamet (cimetidine) and antacids is not recommended, since antacids have been reported to interfere with the absorption of Tagamet (cimetidine).

While healing with Tagamet (cimetidine) often occurs during the first week or two, treatment should be continued for 4 to 6 weeks unless healing has been demonstrated by endoscopic examination.

Maintenance Therapy for Duodenal Ulcer: In those patients requiring maintenance therapy, the recommended adult oral dose is 400 mg at bedtime.

Active Benign Gastric Ulcer

The recommended adult oral dosage for short-term treatment of active benign gastric ulcer is 800 mg h.s., or 300 mg four times a day with meals and at bedtime. Controlled clinical studies were limited to 6 weeks of treatment (see Clinical Trials). 800 mg h.s. is the preferred regimen for most patients based upon convenience and reduced potential for drug interactions.

Symptomatic response to Tagamet (cimetidine) does not preclude the presence of a gastric malignancy. It is important to follow gastric ulcer patients to assure rapid progress to complete healing.

Erosive Gastroesophageal Reflux Disease (GERD)

The recommended adult oral dosage for the treatment of erosive esophagitis that has been diagnosed by endoscopy is 1600 mg daily in divided doses (800 mg b.i.d. or 400 mg q.i.d.) for 12 weeks. The use of Tagamet (cimetidine) beyond 12 weeks has not been established.

Prevention of Upper Gastrointestinal Bleeding

The recommended adult dosing regimen is continuous I.V. infusion of 50 mg/hour. Patients with creatinine clearance less than 30 cc/min. should receive half the recommended dose. Treatment beyond 7 days has not been studied.

Pathological Hypersecretory Conditions

(such as Zollinger-Ellison Syndrome)

Recommended adult oral dosage: 300 mg four times a day with meals and at bedtime. In some patients it may be necessary to administer higher doses more frequently. Doses should be adjusted to individual patient needs, but should not usually exceed 2400 mg per day and should continue as long as clinically indicated.

Parenteral Administration

In hospitalized patients with pathological hypersecretory conditions or intractable ulcers, or in patients who are unable to take oral medication, Tagamet (cimetidine) may be administered parenterally.

The doses and regimen for parenteral administration in patients with GERD have not been established.

All parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration.

Recommendations for parenteral administration

Intramuscular injection

300 mg q 6 to 8 hours (no dilution necessary). Transient pain at the site of injection has been reported.

Intravenous injection

300 mg q 6 to 8 hours. In some patients it may be necessary to increase dosage. When this is necessary, the increases should be made by more frequent administration of a 300 mg dose, but should not exceed 2400 mg per day. Dilute Tagamet (cimetidine hydrochloride) Injection, 300 mg, in Sodium Chloride Injection (0.9%) or another compatible I.V. solution (see Stability of Tagamet (cimetidine) Injection) to a total volume of 20 mL and inject over a period of not less than 5 minutes (see Precautions).

Intermittent intravenous infusion

300 mg q 6 to 8 hours, infused over 15 to 20 minutes. In some patients it may be necessary to increase dosage. When this is necessary, the increases should be made by more frequent administration of a 300 mg dose, but should not exceed 2400 mg per day. Vials: Dilute Tagamet (cimetidine) Injection, 300 mg, in at least 50 mL of 5% Dextrose Injection, or another compatible I.V. solution (see Stability of Tagamet (cimetidine) Injection). Plastic containers: Use premixed Tagamet (cimetidine) Injection, 300 mg, in 0.9% Sodium Chloride in 50 mL plastic containers. ADD-Vantage® Vials: Dilute contents of one vial in an ADD-Vantage® Diluent Container, available in 50 mL and 100 mL sizes of 0.9% Sodium Chloride Injection, and 5% Dextrose Injection.

Continuous intravenous infusion

37.5 mg/hour (900 mg/day). For patients requiring a more rapid elevation of gastric pH, continuous infusion may be preceded by a 150 mg loading dose administered by I.V. infusion as described above. Dilute 900 mg Tagamet (cimetidine) Injection in a compatible I.V. fluid (see Stability of Tagamet (cimetidine) Injection) for constant rate infusion over a 24-hour period. Note: Tagamet (cimetidine) may be diluted in 100 to 1000 mL; however, a volumetric pump is recommended if the volume for 24-hour infusion is less than 250 mL. In one study in patients with pathological hypersecretory states, the mean infused dose of cimetidine was 160 mg/hour with a range of 40 to 600 mg/hour.

These doses maintained the intragastric acid secretory rate at 10 mEq/hour or less. The infusion rate should be adjusted to individual patient requirements.

DIRECTIONS FOR USE OF TAGAMET (cimetidine hydrochloride) INJECTION IN PLASTIC CONTAINERS

To open: Tear overwrap down side at slit and remove solution containers.

Some opacity of the plastic due to moisture absorption during the sterilization process may be observed. This is normal and does not affect solution quality or safety. The opacity will diminish gradually.

Do not add other drugs to premixed Tagamet (cimetidine) Injection in plastic containers.

CAUTION: Check for minute leaks by squeezing inner bag firmly. If leaks are found, discard solution as sterility may be impaired. Additives should not be introduced into this solution. Do not use if the solution is cloudy or precipitated or if the seal is not intact.

Do not use plastic containers in series connections. Such use could result in air embolism due to residual air being drawn from the primary container before administration of the fluid from the secondary container is complete.

Use sterile equipment.

Preparation for administration

1. Suspend container from eyelet support.

2. Remove plastic protector from outlet port at bottom of container.

3. Attach administration set. Refer to complete directions accompanying set.

DIRECTIONS FOR USE OF TAGAMET (cimetidine) ® INJECTION IN ADD-VANTAGE® VIALS are enclosed in ADD-Vantage® Vial packaging.

Stability of Tagamet (cimetidine) Injection

When added to or diluted with most commonly used intravenous solutions, e.g., Sodium Chloride Injection (0.9%), Dextrose Injection (5% or 10%), Lactated Ringer’s Solution, 5% Sodium Bicarbonate Injection, Tagamet (cimetidine hydrochloride) Injection should not be used after more than 48 hours of storage at room temperature.

Tagamet (cimetidine) Injection premixed in plastic containers is stable through the labeled expiration date when stored under the recommended conditions.

Dosage Adjustment for Patients with Impaired Renal Function

Patients with severely impaired renal function have been treated with Tagamet (cimetidine) . However, such usage has been very limited. On the basis of this experience the recommended dosage is 300 mg q 12 hours orally or by intravenous injection. Should the patient’s condition require, the frequency of dosing may be increased to q 8 hours or even further with caution. In severe renal failure, accumulation may occur and the lowest frequency of dosing compatible with an adequate patient response should be used. When liver impairment is also present, further reductions in dosage may be necessary. Hemodialysis reduces the level of circulating Tagamet (cimetidine) . Ideally, the dosage schedule should be adjusted so that the timing of a scheduled dose coincides with the end of hemodialysis.

Patients with creatinine clearance less than 30 cc/min. who are being treated for prevention of upper gastrointestinal bleeding should receive half the recommended dose.

How Supplied

Tablets

Light green, film-coated as follows: 300 mg-round, debossed with the product name TAGAMET (cimetidine) , SB and 300-tablets in bottles of 100; 400 mg-oval-shaped Tiltab®, debossed with the product name, TAGAMET (cimetidine) , SB and 400-tablets in bottles of 60; 800 mg-oval-shaped Tiltab®, debossed with the product name TAGAMET (cimetidine) , SB and 800-tablets in bottles of 30.

Store between 15° and 30°C (59° and 86°F); dispense in a tight light-resistant container.

300 mg 100’s: NDC 0108-5013-20

400 mg 60’s: NDC 0108-5026-18

800 mg 30’s: NDC 0108-5027-13

DATE OF ISSUANCE JUNE 2002, ã2002, GlaxoSmithKline All rights reserved. GlaxoSmithKline, Research Triangle Park, NC 27709 TG:L 93


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

Side Effects

Adverse effects reported in patients taking Tagamet (cimetidine) are described below by body system. Incidence figures of 1 in 100 and greater are generally derived from controlled clinical studies.

Gastrointestinal

Diarrhea (usually mild) has been reported in approximately 1 in 100 patients.

CNS

Headaches, ranging from mild to severe, have been reported in 3.5% of 924 patients taking 1600 mg/day, 2.1% of 2,225 patients taking 800 mg/day and 2.3% of 1,897 patients taking placebo. Dizziness and somnolence (usually mild) have been reported in approximately 1 in 100 patients on either 1600 mg/day or 800 mg/day.

Reversible confusional states, e.g., mental confusion, agitation, psychosis, depression, anxiety, hallucinations, disorientation, have been reported predominantly, but not exclusively, in severely ill patients. They have usually developed within 2 to 3 days of initiation of Tagamet (cimetidine) therapy and have cleared within 3 to 4 days of discontinuation of the drug.

Endocrine

Gynecomastia has been reported in patients treated for 1 month or longer. In patients being treated for pathological hypersecretory states, this occurred in about 4% of cases while in all others the incidence was 0.3% to 1% in various studies. No evidence of induced endocrine dysfunction was found, and the condition remained unchanged or returned toward normal with continuing Tagamet (cimetidine) treatment.

Reversible impotence has been reported in patients with pathological hypersecretory disorders, e.g., Zollinger-Ellison Syndrome, receiving Tagamet (cimetidine) , particularly in high doses, for at least 12 months (range 12 to 79 months, mean 38 months). However, in large-scale surveillance studies at regular dosage, the incidence has not exceeded that commonly reported in the general population.

Hematologic

Decreased white blood cell counts in Tagamet (cimetidine) -treated patients (approximately 1 per 100,000 patients), including agranulocytosis (approximately 3 per million patients), have been reported, including a few reports of recurrence on rechallenge. Most of these reports were in patients who had serious concomitant illnesses and received drugs and/or treatment known to produce neutropenia. Thrombocytopenia (approximately 3 per million patients) and, very rarely, cases of pancytopenia or aplastic anemia have also been reported. As with some other H2-receptor antagonists, there have been extremely rare reports of immune hemolytic anemia.

Hepatobiliary

Dose-related increases in serum transaminase have been reported. In most cases they did not progress with continued therapy and returned to normal at the end of therapy. There have been rare reports of cholestatic or mixed cholestatic-hepatocellular effects. These were usually reversible. Because of the predominance of cholestatic features, severe parenchymal injury is considered highly unlikely. However, as in the occasional liver injury with other H2-receptor antagonists, in exceedingly rare circumstances fatal outcomes have been reported.

There has been reported a single case of biopsy-proven periportal hepatic fibrosis in a patient receiving Tagamet (cimetidine) .

Rare cases of pancreatitis, which cleared on withdrawal of the drug, have been reported.

Hypersensitivity

Rare cases of fever and allergic reactions including anaphylaxis and hypersensitivity vasculitis, which cleared on withdrawal of the drug, have been reported.

Renal

Small, possibly dose-related increases in plasma creatinine, presumably due to competition for renal tubular secretion, are not uncommon and do not signify deteriorating renal function. Rare cases of interstitial nephritis and urinary retention, which cleared on withdrawal of the drug, have been reported.

Cardiovascular

Rare cases of bradycardia, tachycardia and A-V heart block have been reported with H2-receptor antagonists.

Musculoskeletal

There have been rare reports of reversible arthralgia and myalgia; exacerbation of joint symptoms in patients with preexisting arthritis has also been reported. Such symptoms have usually been alleviated by a reduction in Tagamet (cimetidine) dosage. Rare cases of polymyositis have been reported, but no causal relationship has been established.

Integumental

Mild rash and, very rarely, cases of severe generalized skin reactions including Stevens-Johnson syndrome, epidermal necrolysis, erythema multiforme, exfoliative dermatitis and

generalized exfoliative erythroderma have been reported with H2-receptor antagonists. Reversible alopecia has been reported very rarely.

Immune Function

There have been extremely rare reports of strongyloidiasis hyperinfection in immunocompromised patients.

Read the Tagamet (cimetidine) Side Effects Center for a complete guide to possible side effects

Interactions

Tagamet (cimetidine) , apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline and metronidazole, thereby delaying elimination and increasing blood levels of these drugs.

Clinically significant effects have been reported with the warfarin anticoagulants; therefore, close monitoring of prothrombin time is recommended, and adjustment of the anticoagulant dose may be necessary when Tagamet (cimetidine) is administered concomitantly. Interaction with phenytoin, lidocaine and theophylline has also been reported to produce adverse clinical effects.

However, a crossover study in healthy subjects receiving either Tagamet (cimetidine) 300 mg q.i.d. or 800 mg h.s. concomitantly with a 300 mg b.i.d. dosage of theophylline (Theo-Dur®, Key Pharmaceuticals, Inc.) demonstrated less alteration in steady-state theophylline peak serum levels with the 800 mg h.s. regimen, particularly in subjects aged 54 years and older. Data beyond 10 days are not available. (Note: All patients receiving theophylline should be monitored appropriately, regardless of concomitant drug therapy.)

Dosage of the drugs mentioned above and other similarly metabolized drugs, particularly those of low therapeutic ratio or in patients with renal and/or hepatic impairment, may require adjustment when starting or stopping concomitantly administered Tagamet (cimetidine) to maintain optimum therapeutic blood levels.

Alteration of pH may affect absorption of certain drugs (e.g., ketoconazole). If these products are needed, they should be given at least 2 hours before cimetidine administration.

Additional clinical experience may reveal other drugs affected by the concomitant administration of Tagamet (cimetidine) .


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

Warnings

No information provided.

Precautions

General

Rare instances of cardiac arrhythmias and hypotension have been reported following the rapid administration of Tagamet (cimetidine hydrochloride) Injection by intravenous bolus.

Symptomatic response to Tagamet (cimetidine) therapy does not preclude the presence of a gastric malignancy. There have been rare reports of transient healing of gastric ulcers despite subsequently documented malignancy.

Reversible confusional states (see Adverse Reactions) have been observed on occasion, predominantly, but not exclusively, in severely ill patients. Advancing age (50 or more years) and preexisting liver and/or renal disease appear to be contributing factors. In some patients these confusional states have been mild and have not required discontinuation of Tagamet (cimetidine) therapy. In cases where discontinuation was judged necessary, the condition usually cleared within 3 to 4 days of drug withdrawal.

Carcinogenesis, Mutagenesis, Impairment of Fertility

In a 24-month toxicity study conducted in rats, at dose levels of 150, 378 and 950 mg/kg/day (approximately 8 to 48 times the recommended human dose), there was a small increase in the incidence of benign Leydig cell tumors in each dose group; when the combined drug-treated groups and control groups were compared, this increase reached statistical significance. In a subsequent 24-month study, there were no differences between the rats receiving 150 mg/kg/day and the untreated controls. However, a statistically significant increase in benign Leydig cell tumor incidence was seen in the rats that received 378 and 950 mg/kg/day. These tumors were common in control groups as well as treated groups and the difference became apparent only in aged rats.

Tagamet (cimetidine) has demonstrated a weak antiandrogenic effect. In animal studies this was manifested as reduced prostate and seminal vesicle weights. However, there was no impairment of mating performance or fertility, nor any harm to the fetus in these animals at doses 8 to 48 times the full therapeutic dose of Tagamet (cimetidine) , as compared with controls. The cases of gynecomastia seen in patients treated for 1 month or longer may be related to this effect.

In human studies, Tagamet (cimetidine) has been shown to have no effect on spermatogenesis, sperm count, motility, morphology or in vitro fertilizing capacity.

Pregnancy

Teratogenic Effects. Pregnancy Category B : Reproduction studies have been performed in rats, rabbits and mice at doses up to 40 times the normal human dose and have revealed no evidence of impaired fertility or harm to the fetus due to Tagamet (cimetidine) . There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproductive studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

Nursing Mothers

Cimetidine is secreted in human milk and, as a general rule, nursing should not be undertaken while a patient is on a drug.

Pediatric Use

Clinical experience in children is limited. Therefore, Tagamet (cimetidine) therapy cannot be recommended for children under 16, unless, in the judgment of the physician, anticipated benefits outweigh the potential risks. In very limited experience, doses of 20 to 40 mg/kg per day have been used.

Immunocompromised Patients

In immunocompromised patients, decreased gastric acidity, including that produced by acid-suppressing agents such as cimetidine, may increase the possibility of a hyperinfection of strongyloidiasis.


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

OverDose

Studies in animals indicate that toxic doses are associated with respiratory failure and tachycardia that may be controlled by assisted respiration and the administration of a beta-blocker.

Reported acute ingestions orally of up to 20 grams have been associated with transient adverse effects similar to those encountered in normal clinical experience. The usual measures to remove unabsorbed material from the gastrointestinal tract, clinical monitoring and supportive therapy should be employed.

There have been reports of severe CNS symptoms, including unresponsiveness, following ingestion of between 20 and 40 grams of cimetidine, and extremely rare reports following concomitant use of multiple CNS-active medications and ingestion of cimetidine at doses less than 20 grams. An elderly, terminally ill dehydrated patient with organic brain syndrome receiving concomitant antipsychotic agents and Tagamet (cimetidine) 4800 mg intravenously over a 24-hour period experienced mental deterioration with reversal on Tagamet (cimetidine) discontinuation.

There have been two deaths in adults who were reported to have ingested over 40 grams orally on a single occasion.

ContrainDications

Tagamet (cimetidine) is contraindicated for patients known to have hypersensitivity to the product.


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

Clinical Pharamacology

Tagamet (cimetidine) competitively inhibits the action of histamine at the histamine H2 receptors of the parietal cells and thus is a histamine H2-receptor antagonist.

Tagamet (cimetidine) is not an anticholinergic agent. Studies have shown that Tagamet (cimetidine) inhibits both daytime and nocturnal basal gastric acid secretion. Tagamet (cimetidine) also inhibits gastric acid secretion stimulated by food, histamine, pentagastrin, caffeine and insulin.

Antisecretory Activity

1) Acid Secretion : Nocturnal: Tagamet (cimetidine) 800 mg orally at bedtime reduces mean hourly H+ activity by greater than 85% over an 8-hour period in duodenal ulcer patients, with no effect on daytime acid secretion. Tagamet (cimetidine) 1600 mg orally h.s. produces 100% inhibition of mean hourly H+ activity over an 8-hour period in duodenal ulcer patients, but also reduces H+ activity by 35% for an additional 5 hours into the following morning. Tagamet (cimetidine) 400 mg b.i.d. and 300 mg q.i.d. decrease nocturnal acid secretion in a dose-related manner, i.e., 47% to 83% over a 6- to 8-hour period and 54% over a 9-hour period, respectively.

Food Stimulated: During the first hour after a standard experimental meal, oral Tagamet (cimetidine) 300 mg inhibited gastric acid secretion in duodenal ulcer patients by at least 50%. During the subsequent 2 hours Tagamet (cimetidine) inhibited gastric acid secretion by at least 75%.

The effect of a 300 mg breakfast dose of Tagamet (cimetidine) continued for at least 4 hours and there was partial suppression of the rise in gastric acid secretion following the luncheon meal in duodenal ulcer patients. This suppression of gastric acid output was enhanced and could be maintained by another 300 mg dose of Tagamet (cimetidine) given with lunch.

In another study, Tagamet (cimetidine) 300 mg given with the meal increased gastric pH as compared with placebo.

 

Mean Gastric pH

Tagamet

Placebo

1 hour

3.5

2.6

2 hours

3.1

1.6

3 hours

3.8

1.9

4 hours

6.1

2.2

24-Hour Mean H+ Activity: Tagamet (cimetidine) 800 mg h.s., 400 mg b.i.d. and 300 mg q.i.d. all provide a similar, moderate (less than 60%) level of 24-hour acid suppression. However, the 800 mg h.s. regimen exerts its entire effect on nocturnal acid, and does not affect daytime gastric physiology.

Chemically Stimulated: Oral Tagamet (cimetidine) significantly inhibited gastric acid secretion stimulated by betazole (an isomer of histamine), pentagastrin, caffeine and insulin as follows:

Stimulant

Stimulant Dose

Tagamet

% Inhibition

Betazole

1.5mg/kg (sc)

300mg (po)

85% at 2½ hours

Pentagastrin

6mcg/kg/hr (iv)

100mg/hr (iv)

60% at 1 hour

Caffeine

5mg/kg/hr (iv)

300mg (po)

100% at 1 hour

Insulin

0.03 units/kg/hr (iv)

100mg/hr (iv)

82% at 1 hour

When food and betazole were used to stimulate secretion, inhibition of hydrogen ion concentration usually ranged from 45% to 75% and the inhibition of volume ranged from 30% to 65%.

Parenteral administration also significantly inhibits gastric acid secretion. In a crossover study involving patients with active or healed duodenal or gastric ulcers, either continuous I.V. infusion of Tagamet (cimetidine) 37.5 mg/hour (900 mg/day) or intermittent injection of Tagamet (cimetidine) 300 mg q6h (1200 mg/day) maintained gastric pH above 4.0 for more than 50% of the time under steady-state conditions.

2) Pepsin: Oral Tagamet (cimetidine) 300 mg reduced total pepsin output as a result of the decrease in volume of gastric juice.

3) Intrinsic Factor: Intrinsic factor secretion was studied with betazole as a stimulant. Oral Tagamet (cimetidine) 300 mg inhibited the rise in intrinsic factor concentration produced by betazole, but some intrinsic factor was secreted at all times.

Other

Lower Esophageal Sphincter Pressure and Gastric Emptying

Tagamet (cimetidine) has no effect on lower esophageal sphincter (LES) pressure or the rate of gastric emptying.

Pharmacokinetics

Tagamet (cimetidine) is rapidly absorbed after oral administration and peak levels occur in 45 to 90 minutes. The half-life of Tagamet (cimetidine) is approximately 2 hours. Both oral and parenteral (I.V. or I.M.) administration provide comparable periods of therapeutically effective blood levels; blood concentrations remain above that required to provide 80% inhibition of basal gastric acid secretion for 4 to 5 hours following a dose of 300 mg.

Steady-state blood concentrations of cimetidine with continuous infusion of Tagamet (cimetidine) are determined by the infusion rate and clearance of the drug in the individual patient. In a study of peptic ulcer patients with normal renal function, an infusion rate of 37.5 mg/hour produced average steady-state plasma cimetidine concentrations of about 0.9 mcg/mL. Blood levels with other infusion rates will vary in direct proportion to the infusion rate.

The principal route of excretion of Tagamet (cimetidine) is the urine. Following parenteral administration, most of the drug is excreted as the parent compound; following oral administration, the drug is more extensively metabolized, the sulfoxide being the major metabolite. Following a single oral dose, 48% of the drug is recovered from the urine after 24 hours as the parent compound. Following I.V. or I.M. administration, approximately 75% of the drug is recovered from the urine after 24 hours as the parent compound.

CLINICAL TRIALS

Duodenal Ulcer

Tagamet (cimetidine) has been shown to be effective in the treatment of active duodenal ulcer and, at reduced dosage, in maintenance therapy following healing of active ulcers.

Active Duodenal Ulcer: Tagamet (cimetidine) accelerates the rate of duodenal ulcer healing. Healing rates reported in U.S. and foreign controlled trials with Tagamet (cimetidine) are summarized below, beginning with the regimen providing the lowest nocturnal dose.

Duodenal Ulcer Healing Rates with Various Tagamet Dosage Regimens*

Regimen

300 mg q.i.d.

400 mg b.i.d.

800 mg h.s.

1600 mg h.s.

week 4

68%

73%

80%

86%

week 6

80%

80%

89%

week 8

92%

94%

*Averages from controlled clinical trials.

A U.S., double-blind, placebo-controlled, dose-ranging study demonstrated that all once-daily at bedtime (h.s.) Tagamet (cimetidine) regimens were superior to placebo in ulcer healing and that Tagamet (cimetidine) 800 mg h.s. healed 75% of patients at 4 weeks. The healing rate with 800 mg h.s. was significantly superior to 400 mg h.s. (66%) and not significantly different from 1600 mg h.s. (81%).

In the U.S. dose-ranging trial, over 80% of patients receiving Tagamet (cimetidine) 800 mg h.s. experienced nocturnal pain relief after 1 day. Relief from daytime pain was reported in approximately 70% of patients after 2 days. As with ulcer healing, the 800 mg h.s. dose was superior to 400 mg h.s. and not different from 1600 mg h.s.

In foreign, double-blind studies with Tagamet (cimetidine) 800 mg h.s., 79% to 85% of patients were healed at 4 weeks.

While short-term treatment with Tagamet (cimetidine) can result in complete healing of the duodenal ulcer, acute therapy will not prevent ulcer recurrence after Tagamet (cimetidine) has been discontinued. Some follow-up studies have reported that the rate of recurrence once therapy was discontinued was slightly higher for patients healed on Tagamet (cimetidine) than for patients healed on other forms of therapy; however, the Tagamet (cimetidine) -treated patients generally had more severe disease.

Maintenance Therapy in Duodenal Ulcer: Treatment with a reduced dose of Tagamet (cimetidine) has been proven effective as maintenance therapy following healing of active duodenal ulcers.

In numerous placebo-controlled studies conducted worldwide, the percent of patients with observed ulcers at the end of 1 year’s therapy with Tagamet (cimetidine) 400 mg h.s. was significantly lower (10% to 45%) than in patients receiving placebo (44% to 70%). Thus, from 55% to 90% of patients were maintained free of observed ulcers at the end of 1 year with Tagamet (cimetidine) 400 mg h.s.

Factors such as smoking, duration and severity of disease, gender, and genetic traits may contribute to variations in actual percentages.

Trials of other anti-ulcer therapy, whether placebo-controlled, positive-controlled or open, have demonstrated a range of results similar to that seen with Tagamet (cimetidine) .

Active Benign Gastric Ulcer

Tagamet (cimetidine) has been shown to be effective in the short-term treatment of active benign gastric ulcer.

In a multicenter, double-blind U.S. study, patients with endoscopically confirmed benign gastric ulcer were treated with Tagamet (cimetidine) 300 mg four times a day or with placebo for 6 weeks. Patients were limited to those with ulcers ranging from 0.5 to 2.5 cm in size. Endoscopically confirmed healing at 6 weeks was seen in significantly* more Tagamet (cimetidine) -treated patients than in patients receiving placebo, as shown below:

 

Tagamet

Placebo

week 2

14/63 (22%)

7/63 (11%)

total at week 6

43/65 (66%)*

30/67 (45%)

*p<0.05

In a similar multicenter U.S. study of the 800 mg h.s. oral regimen, the endoscopically confirmed healing rates were:

 

Tagamet

Placebo

total at week 6

63/83 (76%)*

44/80 (55%)

*p=0.005

Similarly, in worldwide double-blind clinical studies, endoscopically evaluated benign gastric ulcer healing rates were consistently higher with Tagamet (cimetidine) than with placebo.

Gastroesophageal Reflux Disease

In two multicenter, double-blind, placebo-controlled studies in patients with gastroesophageal reflux disease (GERD) and endoscopically proven erosions and/or ulcers, Tagamet (cimetidine) was significantly more effective than placebo in healing lesions. The endoscopically confirmed healing rates were:

Trial

 

Tagamet (800 mg b.i.d.)

Tagamet (400 mg q.i.d.)

Placebo

p-Value (800 mg b.i.d. vs. placebo)

1

Week 6

45%

52%

26%

0.02

 

Week 12

60%

66%

42%

0.02

2

Week 6

50%

 

20%

<0.01

 

Week 12

67%

 

36%

<0.01

In these trials Tagamet (cimetidine) was superior to placebo by most measures in improving symptoms of day- and night-time heartburn, with many of the differences statistically significant. The q.i.d. regimen was generally somewhat better than the b.i.d. regimen where these were compared.

Prevention of Upper Gastrointestinal Bleeding in Critically Ill Patients

A double-blind, placebo-controlled randomized study of continuous infusion cimetidine was performed in 131 critically ill patients (mean APACHE II score = 15.99) to compare the incidence of upper gastrointestinal bleeding, manifested as hematemesis or bright red blood which did not clear after adjustment of the nasogastric tube and a 5 to 10 minute lavage, persistent Gastroccult® positive coffee grounds for 8 consecutive hours which did not clear with 100 cc lavage and/or which were accompanied by a drop in hematocrit of 5 percentage points, or melena, with an endoscopically documented upper gastrointestinal source of bleed. 14% (9/65) of patients treated with cimetidine continuous infusion developed bleeding compared to 33% (22/66) of the placebo group. Coffee grounds was the manifestation of bleeding that accounted for the difference between groups. Another randomized, double-blind placebo-controlled study confirmed these results for an end point of upper gastrointestinal bleeding with a confirmed upper gastrointestinal source noted on endoscopy, and by post hoc analyses of bleeding episodes between groups.

Pathological Hypersecretory Conditions

(such as ZollingerEllison Syndrome)

Tagamet (cimetidine) significantly inhibited gastric acid secretion and reduced occurrence of diarrhea, anorexia and pain in patients with pathological hypersecretion associated with Zollinger-Ellison Syndrome, systemic mastocytosis and multiple endocrine adenomas. Use of Tagamet (cimetidine) was also followed by healing of intractable ulcers.


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

Patient Information

No information provided. Please refer to the Warnings and Precautions sections.


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.

 

CIMETIDINE - ORAL

 

(sye-MET-uh-deen)

 

COMMON BRAND NAME(S): Tagamet

 

USES: Cimetidine is used to treat ulcers of the stomach and intestines and prevent them from coming back after they have healed. This medication is also used to treat certain stomach and throat (esophagus) problems caused by too much stomach acid (e.g., Zollinger-Ellison syndrome, erosive esophagitis) or a backward flow of stomach acid into the esophagus (acid reflux disease/GERD). Decreasing extra stomach acid can help relieve symptoms such as stomach pain, heartburn, difficulty swallowing, persistent cough, and trouble sleeping. It can also prevent serious acid damage to your digestive system (e.g., ulcers, cancer of the esophagus).

Cimetidine belongs to a class of drugs commonly called H2 blockers. It works by reducing the amount of acid in your stomach.

This medication is also available without a prescription. It is used to treat occasional heartburn caused by too much acid in the stomach (also called acid indigestion or sour stomach). It is also used to prevent heartburn and acid indigestion caused by certain foods and beverages. If you are taking this medication for self-treatment, it is important to read the manufacturer's package instructions carefully so you know when to consult your doctor or pharmacist. (See also Precautions.)

 

HOW TO USE: Take this medication by mouth with or without food as directed by your doctor.

The dosage and length of treatment are based on your medical condition and response to therapy. Follow your doctor's instructions carefully. If you are also taking antacids to relieve stomach pain as recommended by your doctor, separate them from this medication by at least 1 hour.

Take this medication regularly as prescribed in order to get the most benefit from it. To help you remember, take it at the same time(s) each day. Do not increase your dose or take it more often than directed. Continue to take this medication for the prescribed length of treatment even if you are feeling better. Stopping treatment too early may delay the healing process.

If you are using nonprescription cimetidine for self-treatment of acid indigestion or heartburn, take 1 tablet by mouth with a glass of water as needed. To prevent heartburn, take 1 tablet by mouth with a glass of water right before or up to 30 minutes before eating food or drinking beverages that cause heartburn. Do not take more than 2 tablets in 24 hours unless directed by your doctor. Do not take for more than 14 days in a row without talking with your doctor.

Inform your doctor if your symptoms do not improve or if they worsen.

Consumer Overview Side Effect

SIDE EFFECTS: Headache, dizziness, drowsiness, or diarrhea may occur. If any of these effects persist or worsen, notify your doctor or pharmacist promptly.

If your doctor has directed you to use this medication, remember that 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 immediately if any of these unlikely but serious side effects occur: mental/mood changes (e.g., agitation, confusion, depression, hallucinations), trouble urinating, muscle/joint pain, breast swelling/soreness in males, decreased sexual ability (with very high doses of this medication).

Tell your doctor immediately if any of these rare but very serious side effects occur: easy bruising/bleeding, signs of infection (e.g., fever, persistent sore throat, cough, trouble breathing), fast/slow/irregular heartbeat, unusual tiredness, persistent nausea/vomiting, severe stomach/abdominal pain, dark urine, yellowing eyes/skin, change in the amount of urine.

A very serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction include: 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 Tagamet (cimetidine) Side Effects Center for a complete guide to possible side effects

Learn More »

PRECAUTIONS: Before taking cimetidine, tell your doctor or pharmacist if you are allergic to it; or to other H2 blockers (e.g., famotidine, nizatidine, ranitidine); 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: immune system problems, kidney problems, liver problems, certain lung diseases (chronic obstructive pulmonary disease-COPD), diabetes, other stomach problems (e.g., tumors).

Some symptoms may actually be signs of a more serious condition. Get medical help right away if you have: heartburn with lightheadedness/sweating/dizziness, chest/jaw/arm/shoulder pain (especially with shortness of breath, unusual sweating), unexplained weight loss.

In addition, before you self-treat with this medication, get medical help right away if you have any of these signs of a serious condition: trouble/pain swallowing food, bloody vomit, vomit that looks like coffee grounds, bloody/black stools, heartburn for over 3 months, frequent chest pain, frequent wheezing (especially with heartburn), nausea/vomiting, stomach pain.

This drug may make you dizzy or drowsy. 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.

Do not use this medication to treat children younger than 12 unless directed by the doctor.

Older adults may be more sensitive to the side effects of this drug, especially confusion and lung infection (pneumonia). Confusion can increase the risk of falling.

Cimetidine should be used only when clearly needed during pregnancy. Discuss the risks and benefits with your doctor.

Cimetidine passes into breast milk. Consult your doctor before breast-feeding.

Consumer Overview Missed Dose

DRUG INTERACTIONS: See also How to Use section.

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.

This drug should not be used with the following medications because very serious interactions may occur: cisapride, dofetilide, epirubicin.

If you are currently using any of these medications listed above, tell your doctor or pharmacist before starting cimetidine.

Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of: artemether, clopidogrel, carmustine, lumefantrine, metformin, moclobemide, moricizine, procainamide, quinidine, silver sulfadiazine, drugs removed from your body by certain liver enzymes (such as lidocaine, metoprolol, propranolol, tacrine, warfarin, zaleplon, anti-seizure drugs including carbamazepine and phenytoin, benzodiazepines including diazepam, calcium channel blockers including diltiazem, narcotic analgesics including codeine, tricyclic antidepressants including amitriptyline, theophylline and related drugs).

Since cimetidine reduces the amount of acid in your stomach, it may also change the absorption of certain medications and affect how they work. Some examples of affected drugs include atazanavir, dasatinib, delavirdine, certain azole antifungals (such as itraconazole, ketoconazole), among others. Ask your doctor or pharmacist if any of the medications you take are affected by cimetidine and how to manage this interaction.

Check the labels on all your medicines because they may contain nonsteroidal anti-inflammatory drugs (NSAIDs such as aspirin, ibuprofen, naproxen) that may cause stomach irritation/ulcers. Ask your pharmacist about the safe use of those products. Low-dose aspirin should be continued if prescribed by your doctor for specific medical reasons such as heart attack or stroke prevention (usually at dosages of 81-325 milligrams per day). Consult your doctor or pharmacist for more details.

Cigarette smoking can affect this medication. Tell your doctor if you smoke and if you stop or start smoking while using this medication.

This medication and similar H2 blockers (e.g., famotidine, nizatidine, ranitidine) are available both with and without a prescription. Do not take them at the same time.

 

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 mental/mood changes, slurred speech, difficulty awakening.

 

NOTES: Do not share this medication with others.

Lifestyle changes such as stress reduction programs, stopping smoking, limiting alcohol, and diet changes (e.g., avoiding caffeine and spicy foods) may increase the effectiveness of this medication. Talk to your doctor or pharmacist about lifestyle changes that might benefit you.

Laboratory and/or medical tests may be performed to monitor your progress or check for side effects. Consult your doctor for more details.

 

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 in a tightly closed container at room temperature between 59-86 degrees F (15-30 degrees C) away from moisture and light. Do not store in the bathroom. Keep all medicines 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 for more details about how to safely discard your product.

 

Information last revised February 2014. Copyright(c) 2014 First Databank, Inc.

Patient Detailed Side Effect

Brand Names: Tagamet, Tagamet HB

Generic Name: cimetidine (Pronunciation: sye ME ti deen)

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

What is cimetidine (Tagamet)?

Cimetidine is in a group of drugs called histamine receptor antagonists. Cimetidine works by decreasing the amount of acid your stomach produces.

Cimetidine is used to treat and prevent certain types of ulcer, and to treat conditions that cause the stomach to produce too much acid. Cimetidine is also used to treat gastroesophageal reflux disease (GERD), when stomach acid backs up into the esophagus and causes heartburn.

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

Cimetidine 300 mg-MYL

pentagonal, green, imprinted with 317, M

What are the possible side effects of cimetidine (Tagamet)?

Stop using cimetidine and 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.

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

  • cough, fever, chest congestion, trouble breathing;
  • red or blistering skin rash;
  • jaundice (yellowing of the skin or eyes);
  • easy bruising or bleeding, unusual weakness;
  • feeling faint, light-headed, disoriented, or confused;
  • urinating less than usual;
  • irregular heartbeat; or
  • a rash.

Less serious side effects may include:

  • feeling dizzy, depressed, or agitated;
  • breast swelling or tenderness (in men);
  • joint or muscle pain;
  • mild skin rash;
  • headache; or
  • diarrhea, nausea, or constipation.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Read the Tagamet (cimetidine) Side Effects Center for a complete guide to possible side effects

Learn More »

What is the most important information I should know about cimetidine (Tagamet)?

Use this medication exactly as directed on the label, or as your doctor has prescribed it for you. Do not use more of the medication than recommended. Do not use the medication for longer than recommended.

Avoid taking antacids unless your doctor recommends them for heartburn pain. Follow your doctor's advice about the type of antacid to use and when to use it. You may not be able to take the antacid at the same time you take your dose of cimetidine.

Taking cimetidine may make you more susceptible to virus that can cause pneumonia. This has occurred most often in elderly people and in those with diabetes, a weak immune system, or chronic lung disease. Before using cimetidine, tell your doctor if you have any of these conditions.

There are many other drugs that can interact with cimetidine. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

Heartburn can be confused with early symptoms of heart attack. Seek emergency medical attention if you have chest pain or heavy feeling, dizziness, pain spreading to the arm or shoulder, sweating, nausea or vomiting, and a general ill feeling.

Side Effects Centers
  • Tagamet

Patient Detailed How Take

What should I discuss with my healthcare provider before taking cimetidine (Tagamet)?

Heartburn can be confused with early symptoms of heart attack. Seek emergency medical attention if you have chest pain or heavy feeling, dizziness, pain spreading to the arm or shoulder, sweating, nausea or vomiting, and a general ill feeling.

Taking cimetidine may make you more susceptible to virus that causes pneumonia. You may be more likely to develop pneumonia if you have certain health problems.

Ask a doctor or pharmacist if it is safe for you to take cimetidine if you have:

  • diabetes;
  • asthma or a chronic lung disorder;
  • a weak immune system;
  • bone marrow suppression;
  • kidney disease; or
  • liver disease.

Cimetidine is in the FDA pregnancy category B. This means that it is not expected to be harmful to an unborn baby. Do not use this medication without telling your doctor if you are pregnant or plan to become pregnant during treatment.

Cimetidine passes into breast milk, and may be harmful to a nursing baby. Do not take cimetidine without telling your doctor if you are breast-feeding a baby.

Do not give this medicine to a child younger than 16 years old unless your doctor has told you to.

How should I take cimetidine (Tagamet)?

Use this medication exactly as directed on the label, or as your doctor has prescribed it for you. Do not use more of the medication than recommended. Do not use the medication for longer than recommended.

Cimetidine is usually taken with meals or at bedtime.

Take this medicine with a full glass of water.

To be sure you get the correct dose of the oral solution (liquid), 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.

Do not stop taking cimetidine without first talking to your doctor. It may take up to 8 weeks for an ulcer to heal.

Your ulcer may take longer to heal if you smoke cigarettes.

Store cimetidine at room temperature away from moisture, heat, and light.

Side Effects Centers
  • Tagamet

Patient Detailed Avoid Taking

What happens if I miss a dose (Tagamet)?

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 (Tagamet)?

Seek emergency medical attention if you think you have used too much of this medicine. Overdose symptoms may include nausea, vomiting, diarrhea, confusion, extreme weakness, or fainting.

What should I avoid while taking cimetidine (Tagamet)?

If you also take ketoconazole (Nizoral), take it at least 2 hours before you take cimetidine.

Avoid taking antacids unless your doctor recommends them for heartburn pain. Follow your doctor's advice about the type of antacid to use and when to use it. You may not be able to take the antacid at the same time you take your dose of cimetidine.

What other drugs will affect cimetidine (Tagamet)?

Before taking this medication, tell your doctor if you are using any of the following medicines:

  • a blood thinner (warfarin or Coumadin);
  • clopidogrel (Plavix);
  • phenytoin (Dilantin);
  • nifedipine (Adalat);
  • metronidazole (Flagyl);
  • propranolol (Inderal);
  • chlordiazepoxide (Librium);
  • lidocaine (Xylocaine);
  • diazepam (Valium);
  • theophylline (Elixophyllin, Theo-24, Uniphyl); or
  • depression or anxiety medication such as amitriptyline (Elavil), imipramine (Tofranil), clomipramine (Anafranil), desipramine (Norpramin), nortripytyline (Aventyl).

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

Where can I get more information?

Your pharmacist can provide more information about cimetidine.


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: 7.03. 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.

Healthwise

Side Effects Centers
  • Tagamet

Rx Scoops
Featured Topics
Advertisements
Copyrights ©2014: Rx Scoops - Designed & Developed By - GOIGI