Famotidine (Pepcid) Dosing in Adults
The recommended standard dosage of famotidine (Pepcid) for adults with normal renal function is 20 mg twice daily or 40 mg once daily, with specific dosing adjustments required for patients with renal impairment. 1
Standard Dosing by Indication
| Indication | Recommended Dosage | Duration |
|---|---|---|
| Active duodenal ulcer | 40 mg once daily OR 20 mg twice daily | Up to 8 weeks |
| Active gastric ulcer | 40 mg once daily | Up to 8 weeks |
| Symptomatic non-erosive GERD | 20 mg twice daily | Up to 6 weeks |
| Erosive esophagitis | 20 mg twice daily OR 40 mg twice daily | Up to 12 weeks |
| Pathological hypersecretory conditions | Starting: 20 mg every 6 hours (adjust as needed) Maximum: 160 mg every 6 hours | As clinically indicated |
| Prevention of duodenal ulcer recurrence | 20 mg once daily | 1 year or as clinically indicated |
Dosing in Renal Impairment
Dosage adjustments are essential for patients with moderate to severe renal impairment:
Moderate impairment (CrCl 30-60 mL/min):
- Most indications: 20 mg once daily OR 40 mg every other day
- Pathological hypersecretory conditions: Avoid use
Severe impairment (CrCl <30 mL/min):
- Most indications: 20 mg every other day
- Pathological hypersecretory conditions: Avoid use
Special Considerations
NSAID-Associated Ulcers
- For prevention of NSAID-associated ulcers: 40 mg twice daily has been shown to significantly reduce the incidence of both gastric and duodenal ulcers in patients on long-term NSAID therapy 2
- For healing of existing NSAID-associated ulcers: 40 mg twice daily achieves healing rates of 89% at 12 weeks even when patients continue NSAID treatment 3
Erosive Esophagitis
- For erosive/ulcerative reflux esophagitis, 40 mg twice daily is more effective and achieves faster healing than 20 mg twice daily, particularly for more severe cases 4
- Healing rates at 12 weeks: 76% with 40 mg twice daily vs. 67% with 20 mg twice daily
Stress Ulcer Prophylaxis
- For stress ulcer prophylaxis in critically ill patients, low-dose famotidine is recommended (≤40 mg daily) 5
- Discontinue stress ulcer prophylaxis when critical illness resolves or risk factors are no longer present
Administration Considerations
- Can be taken with or without food
- For once-daily dosing, administration at bedtime is common
- For twice-daily dosing, typically given in the morning and evening
- No dosage adjustment needed for hepatic impairment
- Avoid unnecessary polypharmacy; famotidine alone is often sufficient for acid suppression 6
Monitoring
- For patients on long-term therapy, monitor:
- Renal function
- Mental status
- Complete blood count
- Use lowest effective dose for shortest duration necessary 6
Potential Pitfalls
- Renal adjustment errors: Failing to adjust dose in patients with renal impairment can lead to drug accumulation
- Unnecessary combination therapy: Adding a second acid-suppressing medication rarely provides additional benefit if famotidine alone adequately controls symptoms 6
- Prolonged use without indication: Discontinue therapy when no longer clinically indicated to prevent unnecessary medication exposure
Famotidine has a favorable safety profile compared to other H2 receptor antagonists, with higher potency and fewer clinically significant drug interactions, allowing for effective acid suppression at relatively low doses 6, 7.