Famotidine Pediatric Dose Calculator
Calculate famotidine (Pepcid) doses for children based on weight, indication, and formulation using evidence-based pediatric dosing guidelines.
Famotidine Pediatric Dose Calculator
Evidence-based weight-adjusted dosing
How to Use This Calculator
Enter Weight
Input the child's current weight in kilograms for accurate dosing.
Select Indication
Choose between GERD, peptic ulcer, or acid reduction to determine the appropriate dose per kg.
Pick Formulation
Select the available formulation — liquid suspension or tablet strength.
Review Dosing
Check the per-dose and daily totals, along with the recommended frequency and any max-dose warnings.
How We Calculate
Famotidine is an H2-receptor antagonist widely used in pediatric gastroenterology. For GERD in children, the standard dose is 0.5 mg/kg/dose given twice daily, with a maximum of 40 mg per dose per the AAP and NASPGHAN guidelines. Peptic ulcer disease is typically treated with the same 0.5 mg/kg but given once daily at bedtime. Lower prophylactic doses of 0.25 mg/kg/dose BID are used for stress ulcer prevention.
The oral suspension (40 mg/5 mL or 8 mg/mL) is the preferred formulation for younger children who cannot swallow tablets. Tablets (10 mg and 20 mg) are suitable for older children who can swallow pills whole. The calculator automatically caps doses at the adult maximum for each indication.
Famotidine is generally well tolerated in children with a favorable safety profile. Dosing should be confirmed against current hospital formulary guidelines and the prescribing physician's orders. This calculator is for educational and reference purposes only.
Sources & References
- NASPGHAN — Pediatric Gastroesophageal Reflux Clinical Practice Guidelines (naspghan.org)
- Lexicomp Pediatric Drug Information — Famotidine (wolterskluwer.com)
- AAP Pediatric Clinical Practice Guidelines (aap.org)
Data last verified:
Frequently Asked Questions
The standard pediatric GERD dose is 0.5 mg/kg/dose given twice daily (BID). This can be given 15-30 minutes before meals or at consistent times morning and evening. The maximum is 40 mg per dose or 80 mg total per day, which corresponds to the standard adult dosing for GERD. Most children respond well within 2-4 weeks of treatment initiation.
Famotidine tablets can be crushed and mixed with a small amount of soft food or liquid for children who have difficulty swallowing. However, the oral suspension (40 mg/5 mL) is the preferred option for young children as it allows more precise weight-based dosing and is easier to administer. The suspension should be shaken well before measuring each dose.
Famotidine is an H2 blocker that reduces acid production moderately, while omeprazole is a proton pump inhibitor (PPI) that provides more potent and longer-lasting acid suppression. Famotidine is often tried first for mild GERD symptoms. If symptoms persist after 2-4 weeks, physicians may step up to a PPI like omeprazole. Both are considered safe in pediatric populations.
Famotidine is generally well tolerated in children. The most common side effects include headache, dizziness, constipation, and diarrhea. These are typically mild and transient. Rare side effects include rash and elevated liver enzymes. Long-term use of H2 blockers has been associated with vitamin B12 deficiency in adults, though this is less studied in pediatric populations.
For GERD and acid-related conditions, famotidine is most effective when given 15-30 minutes before meals to suppress acid production before food-stimulated acid secretion begins. For bedtime dosing in peptic ulcer treatment, it should be given 30 minutes before the child goes to sleep. Consistency in timing is important for optimal acid suppression.
Famotidine has been used in infants as young as 1 month of age under physician supervision. The dosing is the same weight-based calculation (0.5 mg/kg/dose). However, in neonates and young infants, the prescriber should consider renal function and adjust accordingly. For premature infants, specialized neonatal dosing should be consulted with a pediatric pharmacist.
Famotidine has relatively few significant drug interactions. However, it can reduce the absorption of medications that require an acidic environment, such as ketoconazole and certain iron preparations. These medications should be given 1-2 hours before famotidine. Always inform the prescriber of all current medications to check for potential interactions.
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