What is famotidine, and how does it work (mechanism of action)?
Famotidine is an oral drug that blocks the
production of acid by acid-producing cells in the stomach. It belongs to a class
of drugs called H2 (histamine-2) blockers that also includes cimetidine (Tagamet),
nizatidine (Axid), and ranitidine (Zantac). Histamine is a naturally-occurring
chemical that stimulates cells in the stomach (parietal cells) to produce acid.
H2-blockers inhibit the action of histamine on the cells, thus reducing the
production of acid. Since excessive stomach acid can damage the esophagus,
stomach, and duodenum and lead to inflammation and ulceration, reducing stomach
acid prevents and heals acid-induced inflammation and ulcers. Famotidine was
approved by the FDA in November 1986.
What brand names are available for famotidine?
Pepcid, Pepcid AC, Acid Reducer, Heartburn Relief
Is famotidine available as a generic drug?
GENERIC AVAILABLE: Yes.
Do I need a prescription for famotidine?
Yes, OTC
What are the uses for famotidine?
Famotidine blocks the action of histamine on stomach
cells, and reduces the production of acid by the stomach. Famotidine is useful
in promoting the healing of stomach and duodenal ulcers and in reducing ulcer
pain. Famotidine has been effective in preventing recurrence of ulcers when
given in low doses for prolonged periods of time. Famotidine also is used for
treating heartburn and in healing ulceration and inflammation of the esophagus (esophagitis)
resulting from acid (gastroesophageal reflux disease or GERD). High doses are
used for treating conditions in which there are marked increases in acid
secretion such as Zollinger-Ellison syndrome. Over-the-counter preparations are
used for treatment and prevention of occasional heartburn associated with acid
indigestion (another name for GERD).
What are the side effects of famotidine?
Side effects of famotidine are rare. The most commonly reported minor side effects are:
- constipation,
- diarrhea,
- fatigue,
- headache,
- insomnia,
- muscle pain,
- nausea, and
- vomiting.
Other important side effects include:
- anemia,
- confusion,
- easy bruising or bleeding,
- hair loss,
- rash,
More serious side effects include:
- depression,
- hallucinations,
- irregular heartbeat,
- visual changes, and
- yellowing of the skin or eyes (jaundice).
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What is the dosage for famotidine?
The recommended adult oral dose for treating duodenal ulcers
is 40 mg once daily at bedtime or 20 mg twice daily. Most patients heal their
ulcers within 4 weeks. The regimen for maintenance therapy after the ulcers are
healed is 20 mg once a day at bedtime. The recommended oral dose for adults with
gastric ulcers is, 40 mg once daily at bedtime.
Esophagitis is treated with 20
or 40 mg twice daily for up to 12 weeks. Zollinger-Ellison syndrome is treated
with 20 mg every 6 hours, and doses up to 160 mg every 6 hours have been used in
some patients.
GERD is treated with 20 mg twice daily for up to 6 weeks.
Occasional heartburn is treated with 10-20 mg daily administered 15 to 60
minutes before ingestion of food or beverages that cause heartburn.
QUESTION
GERD is the back up of stomach acid into the esophagus.
See Answer
Which drugs or supplements interact with famotidine?
Famotidine, like other drugs that reduce stomach
acid, may interfere with the absorption of drugs that require acid for adequate
absorption. Examples include iron salts (for example iron sulphate),
itraconazole (Sporanox), and ketoconazole (Nizoral, Extina, Xolegel, Kuric).
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Is famotidine safe to take if I’m pregnant or breastfeeding?
Use of famotidine during
pregnancy has not been adequately
evaluated.
Famotidine is secreted into
breast milk. Due to the
potential but unknown harm that famotidine might cause to the infant, nursing
mothers should consider discontinuing famotidine.
What else should I know about famotidine?
What preparations of famotidine are available?
- Tablets: 10, 20, and 40 mg.
- Tablets (Chewable): 10 and 20 mg.
- Suspension: 40 mg per 5 ml (teaspoon). Injection: 10 mg/ml.
How should I keep famotidine stored?
Tablets and suspension should be stored at room temperature,
15 C – 30 C (59 F – 86 F). Injection should be stored between 2 C – 8 C (36 F – 46 F).