Pediatric Ranitidine Dosing
The recommended pediatric dose of ranitidine is 2-4 mg/kg twice daily for treatment of duodenal and gastric ulcers, and 5-10 mg/kg/day divided into 2 doses for GERD and erosive esophagitis, with a maximum of 300 mg/day. 1
Oral Dosing Guidelines by Indication
- For treatment of duodenal and gastric ulcers: 2-4 mg/kg twice daily to a maximum of 300 mg/day 1
- For maintenance of healing of duodenal and gastric ulcers: 2-4 mg/kg once daily to a maximum of 150 mg/day 1
- For treatment of GERD and erosive esophagitis: 5-10 mg/kg/day, usually given as 2 divided doses 1
Parenteral (Intramuscular) Dosing
- For IM administration (such as in anaphylaxis management): 1 mg/kg per dose 2
- Maximum single IM dose should not exceed 50 mg, even in larger children 2
Age-Specific Considerations
- For neonates (less than 1 month of age): Insufficient pharmacokinetic data exists to make specific dosing recommendations 1
- For preterm infants: 0.5 mg/kg twice daily has been shown to maintain gastric pH >4 3
- For term infants: 1.5 mg/kg three times daily is recommended to maintain gastric pH >4 3
- For critically ill children: A minimum of 3 mg/kg/day of intravenous ranitidine is needed for adequate gastric pH control 4
Administration Considerations
- Oral ranitidine is approximately 50% absorbed after administration 1
- Food or antacids do not significantly impair absorption 1
- In pediatric patients, the average bioavailability of oral ranitidine is 48%, comparable to adults 1
- For critically ill children requiring stress ulcer prophylaxis, 1.5 mg/kg IV every 6 hours has been shown to maintain gastric pH ≥4 in 80% of patients 5
Special Populations
- For patients with impaired renal function (creatinine clearance <50 mL/min): Dose adjustment is required - 150 mg every 24 hours is recommended 1
- For patients on hemodialysis: Dosing schedule should be adjusted so that the timing of a scheduled dose coincides with the end of hemodialysis 1
Monitoring and Efficacy
- A single 75 mg dose of ranitidine has been shown to significantly increase intragastric pH for 5-6 hours in children aged 4-11 years 6
- For critically ill children, gastric pH should be monitored to ensure adequate acid suppression (pH >4) 4
- If gastric pH control is inadequate, consider increasing the dose to at least 3 mg/kg/day 4
Important Considerations
- Ranitidine clearance in pediatric patients correlates with renal function 7
- The effect of a single dose lasts longer in preterm than in term infants 3
- The time needed to reach maximum gastric pH is significantly longer in preterm than in term infants 3
Always monitor for therapeutic response and adjust dosing as needed based on clinical response and gastric pH measurements when appropriate.