Famotidine Dosage

Usual Adult Dose for Duodenal Ulcer

Initial:
Parenteral: 20 mg IV every 12 hours. Alternatively, some clinicians recommend a continuous IV infusion of 3.2 mg/hour for up to 72 hours following a 10 mg IV bolus dose.

Oral: 40 mg orally once a day at bedtime or 20 mg orally twice a day.

Maintenance: 20 mg orally or IV once a day at bedtime.

Usual Adult Dose for Peptic Ulcer

Initial:
Parenteral: 20 mg IV every 12 hours. Alternatively, some clinicians recommend a continuous IV infusion of 3.2 mg/hour for up to 72 hours following a 10 mg IV bolus dose.

Oral: 40 mg orally once a day at bedtime or 20 mg orally twice a day.

Maintenance: 20 mg orally or IV once a day at bedtime.

Usual Adult Dose for Duodenal Ulcer Prophylaxis

20 mg orally or IV, once a day.

Usual Adult Dose for Gastric Ulcer

Parenteral: 20 mg IV every 12 hours. Alternatively, some clinicians recommend a continuous IV infusion of 3.2 mg/hour for up to 72 hours following a 10 mg IV bolus dose.

Oral: 40 mg orally once a day at bedtime or 20 mg orally twice a day.

Usual Adult Dose for Gastroesophageal Reflux Disease

Parenteral: 20 mg IV every 12 hours. Alternatively, some clinicians recommend a continuous IV infusion of 3.2 mg/hour for up to 72 hours following a 10 mg IV bolus dose.

Oral: 20 mg orally twice a day for up to 6 weeks.

Usual Adult Dose for Erosive Esophagitis

Parenteral: 20 mg IV every 12 hours. Alternatively, some clinicians recommend a continuous IV infusion of 3.2 mg/hour for up to 72 hours following a 10 mg IV bolus dose.

Oral: 20 to 40 mg orally twice a day for up to 12 weeks.

Usual Adult Dose for Zollinger-Ellison Syndrome

Parenteral: 20 mg IV every 6 hours. Alternatively, some clinicians recommend a continuous IV infusion of 3.2 mg/hour for up to 72 hours following a 10 mg IV bolus dose.

Oral:
Initial: 20 mg orally every 6 hours.
Maintenance: Dosage adjustments are made to control gastric acid secretion. Doses up to 160 mg every 6 hours have been used.

Usual Adult Dose for Pathological Hypersecretory Conditions

Parenteral: 20 mg IV every 6 hours. Alternatively, some clinicians recommend a continuous IV infusion of 3.2 mg/hour for up to 72 hours following a 10 mg IV bolus dose.

Oral:
Initial: 20 mg orally every 6 hours.
Maintenance: Dosage adjustments are made to control gastric acid secretion. Doses up to 160 mg every 6 hours have been used.

Usual Adult Dose for Dyspepsia

10 mg orally once or twice daily.

Usual Adult Dose for Upper GI Hemorrhage

20 mg IV every 12 hours. Alternatively, some clinicians recommend a continuous IV infusion of 3.2 mg/hour for up to 72 hours following a 10 mg IV bolus dose.

Usual Adult Dose for Urticaria

Study (n=25)
Less than 72 hour duration: 20 mg IM once.

Usual Pediatric Dose for Peptic Ulcer

Peptic ulcer disease:
Oral:
Children and Adolescents 1 to 16 years: 0.5 mg/kg/day once daily at bedtime or divided twice daily (maximum daily dose: 40 mg/day)
Doses up to 1 mg/kg/day have been used

Stress ulcer prophylaxis, gastric acid suppression:
IV: 0.5 to 1 mg/kg/dose every 12 hours (maximum dose: 20 mg/dose)

Hypersecretory conditions:
Oral:
Adolescents:
Initial: 20 mg every 6 hours. May increase up to 160 mg every 6 hours.

Usual Pediatric Dose for Gastroesophageal Reflux Disease

Infants 1 to 3 months:
Oral:
GERD: 0.5 mg/kg/dose once daily for up to 8 weeks
Infants 3 months to 1 year:
Oral:
GERD: 0.5 mg/kg/dose twice daily for up to 8 weeks

Children 1 to 16 years:
Oral:
GERD: 0.5 mg/kg/dose 2 times a day (doses up to 1 mg/kg/dose 2 times a day have been reported).
Maximum: 40 mg/dose

Patients unable to take oral medication:
IV:
Infants: 0.25 to 0.5 mg/kg/dose once daily
Children and Adolescents 1 to 16 years:
Initial dose: 0.25 mg/kg/dose every 12 hours (maximum dose: 20 mg/dose). Doses up to 0.5 mg/kg/dose every 12 hours have been reported.

Usual Pediatric Dose for Dyspepsia

Greater than 12 years:
Acid indigestion, heartburn, or sour stomach (OTC use): 10 to 20 mg 15 to 60 minutes before eating; not more than 2 tablets per day.

Renal Dose Adjustments

In moderate renal insufficiency (CrCl less than 50 mL/min) or severe renal insufficiency (CrCl less than 10 mL/min) the recommended dose may be cut in half or the dosing interval prolonged to 36 to 48 hours.

Liver Dose Adjustments

No adjustments recommended

Dose Adjustments

Studies in children suggest that dosing intervals of 8 hours would benefit most patients, because the observed duration of effective acid suppression (intragastric pH greater than or equal to 4) appears to be approximately 5 to 9 hours,

Precautions

Because CNS adverse effects have been reported in patients with moderate to severe renal insufficiency, a longer dose interval and/or a lower dose is necessary as indicated by clinical response.

Any gastric malignancies must be ruled out before the start of famotidine treatment, since symptom relief may delay proper and timely diagnosis.

Dialysis

No data available

Other Comments

A total of 6 to 8 weeks of famotidine therapy is usually sufficient for ulcer healing. Length of therapy for erosive esophagitis generally should not exceed 12 weeks.

Agents in this class of drugs (H2 antagonists) have not demonstrated unequivocal efficacy in the treatment of upper gastrointestinal hemorrhage, nor are they approved by the FDA for use in this setting. However, some clinicians use intravenous H2 antagonists as part of the therapeutic approach to treating upper gastrointestinal hemorrhage.

See also...