Lactulose Dosing for a 5-Month-Old Infant
For this 5-month-old infant (6.5 kg), administer lactulose 2.5 to 10 mL daily in divided doses, starting at the lower end of this range (2.5-5 mL daily split into 2 doses) and titrating upward based on response. 1
Weight-Based Dosing Recommendation
- Initial dose: Start with 2.5 mL twice daily (total 5 mL/day) for this 6.5 kg infant 1
- Dose range: The FDA-approved pediatric dosing for infants is 2.5 to 10 mL daily in divided doses 1
- Titration: Adjust the dose every 1-2 days to produce 2-3 soft stools daily 1
Administration Schedule
- Frequency: Divide the total daily dose into 2-3 administrations throughout the day 1
- For this infant: Give 2.5 mL every 12 hours initially, which can be increased to 5 mL every 12 hours (10 mL total daily) if needed 1
- Goal: Achieve 2-3 soft stools per day without causing diarrhea 1
Critical Dosing Adjustments
- If diarrhea occurs: Reduce the dose immediately 1
- If diarrhea persists: Discontinue lactulose 1
- Maximum consideration: Do not exceed 10 mL daily for an infant of this age without clear clinical indication 1
Practical Calculation for This Patient
Using the lactulose 10 gram/15 mL oral solution:
- Starting regimen: 2.5 mL twice daily (morning and evening)
- If inadequate response after 2 days: Increase to 3.75 mL twice daily
- Maximum for this infant: 5 mL twice daily (10 mL total/day) 1
Common Pitfalls to Avoid
- Avoid starting at high doses: Begin conservatively at 2.5 mL twice daily rather than jumping to the maximum 10 mL/day, as infants are more sensitive to osmotic effects 1
- Monitor stool frequency closely: The goal is 2-3 soft stools daily, not continuous diarrhea 1
- Do not continue if severe diarrhea develops: This can lead to dehydration and electrolyte imbalances in infants 1
Clinical Monitoring
- Assess response within 24-48 hours: Some infants may not respond for up to 48 hours or longer 1
- Watch for adverse effects: Flatulence, cramping, and diarrhea are dose-related effects that indicate the need for dose reduction 2, 3
- Hydration status: Monitor for signs of dehydration if multiple loose stools occur 1