FAMOTIDINE (Pepcid): What is used for?

What is Famotidine?

Famotidine is an active ingredient used for the treatment of gastric ulcer, GERD, Zollinger-Ellison Syndrome and heartburn.

The brand names of Famotidine in the United States are: Pepcid, Pepcid AC, Heartburn Relief and Fluxid.

Famotidine Mechanism of Action (MOA)

After oral administration, its action begins quickly and, at the recommended doses, it has a prolonged and very effective effect at relatively low blood concentrations.
The duration of its action, its concentration in the plasma and its recovery of urine are dose-related.
Famotidine decreases the acid and pepsin content and the volume of basal, nocturnal and stimulated gastric secretion.

Therapeutic indications, uses and benefits of Famotidine

  • Duodenal ulcer.
  • Benign gastric ulcer.
  • Hypersecretary syndromes such as Zollinger-Ellison syndrome.
  • Prevention of duodenal ulcer recurrence.
  • Prevention of recurrence of benign gastric ulcer.
  • Symptomatic treatment of GERD that has not responded to hygienic-dietary measures and antacids.
  • Esophagitis due to gastroesophageal reflux.
  • Relief and symptomatic treatment of heartburn in adults and children over 16 years of age.

Dosage of Famotidine



– Duodenal ulcer: Initial: 40 mg/24 h at night or 20 mg/12 h, 4-8 weeks.
Maintenance to reduce recurrences: 20 mg/24 h at night; minimum 1 year.

– Benign gastric ulcer: 40 mg/24 h at night, 4-8 weeks. Maintenance to reduce recurrences: 20 mg/24 h at night; minimum 1 year.

– Treatment of GERD: 20 mg/12 h.

– Esophagitis due to gastroesophageal reflux: 40 mg/12 h.
If no response is obtained at 4-8 weeks, make endoscopic diagnosis.

– S. Zollinger-Ellison: 20 mg/6 h; maximum: 800 mg/day.

– Relief and symptomatic treatment of heartburn and burning: over 16 years: 10 mg when symptoms are present or 10 mg 1 hour before eating; maximum: 20 mg/day; maximum: 1 week.

Kidney failure: if Clcr < 50 ml/min, reduce to ½ dose or increase interval between doses to 36-48 h.

Mode of administration

Oral use.

Contraindications of Famotidine

Hypersensitivity to famotidine and other H2 receptor antagonists.

Warnings and Precautions with Famotidine

  • To rule out the existence of gastric neoplasia before starting treatment.
  • Safety and efficacy in children have not been established.
  • Elderly people.
  • Gradually stop treatment.
  • Kidney failure or moderate or severe liver failure.
  • Maximum duration of treatment 1 week.
  • Stop treatment and re-evaluate the clinical situation if symptoms persist or worsen.

Liver failure

Caution in moderate or severe liver failure.

Kidney failure

Caution with moderate or severe renal failure.
If Clcr < 50 ml/min, reduce to ½ dose or increase interval between doses to 36-48 hours.

Interactions with Famotidine

  • Decreases absorption of: ketoconazole and itraconazole (give famotidine 2 hours later); salts of Fe.
  • Decreased absorption with: antacids (spacing 1 hour).
  • Risk of loss of efficacy of: calcium carbonate (when administered as a chelator in hemodialysis patients).
  • Lab: do not administer during the 24 hours preceding the gastric acid secretion test; causes false – in skin tests with allergen extracts; possible increase in serum transaminases.

Pregnancy and Famotidine

Not recommended, only prescribe when absolutely necessary.
Assess benefit/risk.


Famotidine has been detected in breast milk.
Breastfeeding mothers should discontinue treatment with famotidine or stop breastfeeding.

Effects on driving ability

Although no such effects are to be expected, if dizziness, fatigue or drowsiness occur, do not drive or use dangerous machinery.

Adverse reactions and side effects of Famotidine

  • Headache.
  • Dizziness.
  • Diarrhea.
  • Constipation.


Source: The content of this active ingredient has been written taking into account the clinical and molecular information of all medicines authorised and marketed in the United States under the Unique Ingredient Identifier (UNII) by the Substance Registration System (SRS) of the Food and Drug Administration (FDA) and the United States Pharmacopeia (USP).

In order to know in detail the information authorized by the FDA for each drug, you should consult the corresponding medication guide authorized by the FDA.


NCI Thesaurus: C29045


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