Famotidine Dosing for Infants
The recommended dose of Pepcid (famotidine) for infants is 0.5 mg/kg/dose given twice daily, with potential need for individualization up to 1.0 mg/kg/dose based on clinical response. 1
Dosing Guidelines
Standard Dosing
- Initial dose: 0.5 mg/kg/dose twice daily
- Maximum dose: May increase to 1.0 mg/kg/dose if needed for better symptom control
Age-Specific Considerations
- Infants <3 months: Once daily dosing may be sufficient due to decreased clearance 2
- Infants >3 months: Twice daily dosing (every 12 hours) is typically required 2
Administration
- Can be administered orally or intravenously depending on clinical situation
- For oral administration in infants, use an appropriate measuring device such as a 3-mL or 5-mL oral syringe for accurate dosing
Clinical Evidence
The dosing recommendation is based on a multi-center, randomized controlled trial that specifically evaluated famotidine in infants with gastroesophageal reflux disease (GERD). This study found that:
- 0.5 mg/kg/dose showed significant improvement in regurgitation frequency
- 1.0 mg/kg/dose showed significant improvements in crying time, regurgitation frequency, and volume
- Higher doses may be more efficacious in some infants, suggesting the need for dose individualization 1
A pharmacokinetic study in infants demonstrated that:
- Infants <3 months have decreased plasma and renal clearance of famotidine
- Infants >3 months show pharmacokinetic parameters similar to older children and adults
- No drug accumulation was observed with multiple dosing 2
Safety Considerations
Potential Adverse Effects
- Agitation or irritability (may manifest as head-rubbing)
- Somnolence
- Anorexia
- Headache (difficult to assess in infants)
- Vomiting
- Hiccups
- Candidiasis 1
Monitoring
- Monitor for improvement in reflux symptoms (decreased regurgitation, improved feeding, decreased crying)
- Observe for potential adverse effects, particularly behavioral changes
- No significant changes in vital signs (respiration, heart rate, blood pressure) have been reported with appropriate dosing 3
Important Considerations
- Famotidine is an H2-receptor antagonist that works by reducing gastric acid production
- Unlike proton pump inhibitors (such as omeprazole), which may require higher weight-based dosing in infants (0.7-2.8 mg/kg/day) 4, famotidine typically requires lower doses
- For intravenous administration in neonates with stress ulcers, a dosage of 0.5 mg/kg every 12 hours has been shown to be effective and safe 3
Clinical Pearls
- Famotidine has a better safety profile than first-generation H2 blockers
- Oral bioavailability is approximately 99.5% in infants, making oral administration equally effective to IV when the enteral route is available 2
- Renal function is the primary determinant of famotidine clearance in infants, so dose adjustments may be needed in infants with renal impairment
Always assess clinical response after initiating therapy and adjust dosing as needed based on symptom improvement and tolerability.