Lactulose Dosing for Pediatric Patients
For pediatric constipation, lactulose dosing is age-dependent: infants require 2.5-10 mL daily in divided doses, while older children and adolescents need 40-90 mL total daily dose, titrated to produce 2-3 soft stools daily. 1
Age-Specific Dosing Guidelines
Infants (Under 1 Year)
- Initial dose: 2.5-10 mL daily in divided doses 1
- Lactulose and lactitol-based medications are authorized and effective before 6 months of age 2
- If diarrhea occurs, reduce the dose immediately and discontinue if diarrhea persists 1
Older Children and Adolescents
- Total daily dose: 40-90 mL 1
- The subjective goal is to produce 2-3 soft stools daily, same as adults 1
- Dose adjustments should be made based on clinical response 1
Dosing for Specific Indications
Functional Constipation (Standard Treatment)
- Lactulose (10 g/15 mL solution): 1.3 g/kg/day divided twice daily, up to maximum 20 g 3
- Alternative dosing: 0.7-2.0 g/kg/day 4
- Treatment requires sufficient dose for prolonged duration to be effective 2
Fecal Disimpaction
- High-dose lactulose: 4-6 mL/kg/day (maximum 120 mL/day) until resolution or up to 6 days 5
- This higher dosing is specifically for disimpaction therapy, not maintenance 5
- All patients achieved successful disimpaction by day 7 in clinical trials 5
Critical Dosing Principles
Titration Strategy
- Start at the lower end of the dosing range 1
- Adjust dose every 1-3 days based on stool frequency and consistency 1, 6
- Target outcome: 2-3 soft, formed stools daily 1
- If excessive bowel movements occur (>3 per day), reduce dose immediately 1
Duration of Therapy
- The rule for treatment is sufficient dose for a long time 2
- Maintenance therapy typically continues for weeks to months 2
- Premature discontinuation leads to relapse 2
Comparative Efficacy Considerations
Lactulose vs. Polyethylene Glycol (PEG)
- PEG shows faster response time and earlier symptom relief compared to lactulose 5, 4
- PEG significantly reduces painful bowel movements (43.8% vs 73.3% with lactulose at week 1) 4
- However, lactulose is cheap, widely available, and effective as an alternative when PEG is unavailable 5
- Both agents are safe and well-tolerated in pediatric populations 5
Lactulose vs. Mineral Oil
- Liquid paraffin (mineral oil) shows more rapid response than lactulose in the first 4 weeks 6
- Lactulose has higher side-effect rates affecting compliance (90% vs 60% compliance in last 4 weeks) 6
- Late response and side-effects with lactulose can influence treatment success 6
Common Pitfalls and Safety Considerations
Dose-Related Adverse Effects
- Bloating and flatulence are common dose-dependent side effects 7, 8
- Diarrhea indicates excessive dosing—reduce immediately 1
- Overuse can cause dehydration and electrolyte disturbances 7, 8
Treatment Failure Management
- If no response after appropriate dosing, do not escalate indefinitely 8
- Investigate for underlying issues rather than simply increasing lactulose dose 8
- Consider switching to PEG if lactulose fails or causes intolerable side effects 2, 4
Age-Specific Cautions
- Very little information exists on lactulose use in young children and adolescents compared to adults 1
- Polyethylene glycol is authorized for infants over 6 months as an alternative 2
- Monitor closely for dehydration in younger infants due to higher fluid turnover 7
Practical Administration Tips
Formulation Considerations
- Standard concentration: 10 g lactulose per 15 mL solution 1, 5
- Can be mixed with water, juice, or milk to improve palatability 1
- Divided dosing (2-3 times daily) improves tolerance and compliance 3