Lactulose (Duphalac) Dosage for Constipation in a 6-Year-Old Child
For a 6-year-old child with constipation, the recommended initial dose of lactulose (Duphalac) is 5-10 mL (3.3-6.7 g) daily, which can be adjusted based on response to achieve 2-3 soft stools daily.
Dosing Guidelines for Lactulose in Children
The FDA-approved dosing recommendations for lactulose in pediatric patients are as follows 1:
- Infants: 2.5-10 mL daily in divided doses
- Older children and adolescents: 40-90 mL total daily dose
- Initial dosing principle: Start at the lower end of the range and titrate based on response
- Goal of therapy: Production of 2-3 soft stools daily
Specific Dosing for a 6-Year-Old
For a 6-year-old child specifically:
- Starting dose: 5-10 mL (approximately 3.3-6.7 g) once daily, preferably at night
- Titration: Increase by 5 mL every 1-2 days until achieving 2-3 soft stools daily
- Maximum daily dose: Generally not exceeding 40 mL for a child this age
Administration Tips
- Lactulose can be mixed with water, milk, or fruit juice to improve palatability
- If the initial dose causes diarrhea, reduce the dose immediately
- If diarrhea persists despite dose reduction, discontinue lactulose 1
- Administer as a single daily dose or divided into two doses for better tolerance
Monitoring and Duration
- Assess response within 24-48 hours after starting treatment
- If no response is seen within 48 hours, consider adding a stimulant laxative 2
- Optimal initial treatment duration is 4 weeks
- Periodic evaluation every 4-6 weeks is recommended for continued treatment 2
Important Considerations and Potential Side Effects
- Common side effects: Bloating and flatulence (dose-dependent) 2
- Monitoring: Ensure adequate hydration to optimize effect 2
- Taste concerns: Lactulose has a sweet taste but may not be well-accepted by all children
Alternative Treatment Options
While lactulose is effective, polyethylene glycol (PEG) has shown superior efficacy in pediatric constipation:
- PEG has demonstrated higher success rates with fewer side effects compared to lactulose 3
- PEG is associated with less abdominal pain, straining, and pain during defecation 3
- For children >6 months, PEG at a dose of 0.78 g/kg/day has been shown to be safe and effective 4
Clinical Pearls
- Start with lower doses and gradually titrate to improve tolerability
- Lactulose is safe for long-term use in children
- Ensure the child maintains adequate fluid intake while on lactulose
- Monitor for excessive gas, bloating, or abdominal discomfort, which may require dose adjustment
- If constipation is severe with fecal impaction, consider initial disimpaction before maintenance therapy