Famotidine — uses, dosing, side effects & the brands that sell it · pharmaranks
Famotidine: uses, dosing, side effects & brands
Famotidine is a histamine-2 receptor antagonist sold in the U.S. under 7 brand and generic names, for duodenal ulcer, dyspepsia and peptic esophagitis. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
By the pharmaranks editorial team·Reviewed against the FDA (openFDA label, NDC Directory & Enforcement) sources·How we research
7 products — Pepcid Preservative Free, Pepcid Preservative Free in Plastic Container and Pepcid Rpd, and others
Prescription?
Both Rx and OTC forms
Generic available?
Yes
Typical price
about $2 for a 30-count supply
How famotidine is dosed
From the FDA label for Pepcid Preservative Free (application NDA019510). Other famotidine products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
In some hospitalized patients with pathological hypersecretory conditions or intractable ulcers, or in patients who are unable to take oral medication, Famotidine Injection may be administered until oral therapy can be instituted. The recommended dosage for Famotidine Injection in adult patients is 20 mg intravenously q 12 h. The doses and regimen for parenteral administration in patients with GERD have not been established. Dosage for Pediatric Patients <1 Year of Age Gastroesophageal Reflux Disease (GERD) See PRECAUTIONS, Pediatric Patients <1 Year of Age . The studies described in PRECAUTIONS, Pediatric Patients <1 Year of Age suggest the following starting doses in pediatric patients <1 year of age: Gastroesophageal Reflux Disease (GERD) - 0.5 mg/kg/dose of famotidine oral suspension for the treatment of GERD for up to 8 weeks once daily in patients <3 months of age and 0.5 mg/kg/dose twice daily in patients 3 months to <1 year of age. Patients should also be receiving conservative measures (e.g., thickened feedings). The use of intravenous famotidine in pediatric patients <1 year of age with GERD has not been adequately studied. Dosage for Pediatric Patients 1 to 16 Years of Age See PRECAUTIONS, Pediatric Patients 1 to 16 Years of Age . The studies described in PRECAUTIONS, Pediatric Patients 1 to 16 Years of Age suggest that the starting dose in pediatric patients 1 to…
Famotidine side effects
The adverse reactions listed below have been reported during domestic and international clinical trials in approximately 2,500 patients. In those controlled clinical trials in which famotidine tablets were compared to placebo, the incidence of adverse experiences in the group which received famotidine tablets, 40 mg at bedtime, was similar to that in the placebo group. The following adverse reactions have been reported to occur in more than 1% of patients on therapy with famotidine in controlled clinical trials, and may be causally related to the drug: headache (4.7%), dizziness (1.3%), constipation (1.2%) and diarrhea (1.7%). The following other adverse reactions have been reported infrequently in clinical trials or since the drug was marketed. The relationship to therapy with famotidine has been unclear in many cases. Within each category the adverse reactions are listed in order of decreasing severity. Body as a Whole: fever, asthenia, fatigue Cardiovascular: arrhythmia, AV block, palpitation, prolonged QT interval Gastrointestinal: cholestatic jaundice, hepatitis, elevated liver enzyme, vomiting, nausea, abdominal discomfort, anorexia, dry mouth Hematologic: agranulocytosis, pancytopenia, leukopenia, thrombocytopenia Hypersensitivity: anaphylaxis, angioedema, orbital or facial edema, urticaria, rash, conjunctival injection, bronchospasm Musculoskeletal: rhabdomyolysis,…
Every famotidine product we track (7)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
The active ingredient in Famotidine Injection, USP is a histamine H 2 -receptor antagonist. Famotidine is [1-Amino-3-[[[2-[(diaminomethylene)amino]-4-thiazolyl]methyl]thio] propylidene] sulfamide. Its structural formula is: C 8 H 15 N 7 O 2 S 3 MW 337.45 Famotidine is a white to pale yellow crystalline compound that is freely soluble in glacial acetic acid, slightly soluble in methanol, very slightly soluble in water, and practically insoluble in ethanol. Famotidine Injection is supplied as a sterile concentrated solution for intravenous injection. Each mL of the single-dose solution contains 10 mg of famotidine and the following inactive ingredients: L-aspartic acid 4 mg, mannitol 20 mg, and Water for Injection q.s. 1 mL. The multi-dose solution also contains benzyl alcohol 0.9% added as preservative. Structural Formula
What kind of drug is famotidine?
The FDA classifies famotidine as a histamine-2 receptor antagonist. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.
Can you take famotidine with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run famotidine against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What brand names is famotidine sold under?
We track 7 famotidine-containing products in the U.S.: Pepcid Preservative Free, Pepcid Preservative Free in Plastic Container, Pepcid Rpd, Famotidine, Fluxid, Pepcid and Pepcid Ac. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.
What forms does famotidine come in?
Across the brands we track, famotidine is currently marketed as injectable, tablet, orally disintegrating, solution, powder and tablet, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Who shouldn’t take famotidine
Hypersensitivity to any component of these products. Cross sensitivity in this class of compounds has been observed. Therefore, Famotidine Injection should not be administered to patients with a history of hypersensitivity to other H 2 -receptor antagonists.
Famotidine drug interactions
No drug interactions have been identified. Studies with famotidine in man, in animal models, and in vitro have shown no significant interference with the disposition of compounds metabolized by the hepatic microsomal enzymes, e.g., cytochrome P450 system. Compounds tested in man include warfarin, theophylline, phenytoin, diazepam, aminopyrine and antipyrine. Indocyanine green as an index of hepatic drug extraction has been tested and no significant effects have been found.
Yes. Our catalog lists 1 generic famotidine product alongside the brand versions. A generic has the same active ingredient and must meet the FDA's bioequivalence standard; it usually costs less. Ask your pharmacist which one your plan covers.
Has famotidine been recalled?
The FDA's Enforcement database lists 1 recall record whose product description mentions famotidine. The most recent: Famotidine Injection (Nov 6, 2025). A recall applies to specific lots, not to the drug as a whole — check the record for the affected lot numbers.