Lactulose Dosage for a 6-Year-Old Child with Constipation
For a 6-year-old child with constipation, the recommended initial daily oral dose of lactulose (Duphalac) is 40-90 mL divided into multiple doses throughout the day. 1
Dosing Guidelines
The FDA-approved lactulose dosing for pediatric patients provides the following recommendations:
- For infants: 2.5-10 mL daily in divided doses
- For older children and adolescents (including 6-year-olds): 40-90 mL total daily dose 1
Administration Tips:
- Start at the lower end of the dosing range (40 mL/day) and adjust as needed
- Divide the total daily dose into 2-3 administrations
- The goal of treatment is to produce 2-3 soft stools daily 1
- If diarrhea occurs, reduce the dose immediately
- If diarrhea persists despite dose reduction, discontinue lactulose 1
Monitoring and Adjustments
- Assess response after 24-48 hours
- Adjust dosage every 1-2 days until achieving 2-3 soft stools daily
- Monitor for side effects, particularly abdominal pain, bloating, and flatulence 2
Important Considerations
- Lactulose is an osmotic laxative that can be used in children with constipation 3
- It is authorized and effective for children under 6 months of age, making it appropriate for a 6-year-old 3
- For children over 6 months, polyethylene glycol (PEG) is also an option and may be more effective 4
Comparative Efficacy
Studies comparing lactulose with other laxatives have shown:
- PEG 3350 provides higher success rates with fewer side effects compared to lactulose 4
- In a randomized controlled trial, PEG 3350 showed a success rate of 56% compared to 29% with lactulose 4
- Lactulose has been shown to be more effective than senna for producing normal stools in children 5
Potential Side Effects
- Common side effects include bloating and flatulence (dose-dependent) 2
- Abdominal pain and cramping may occur
- Bad taste is a common complaint 4
Treatment Duration
- The rule for treatment of constipation is "sufficient dose for a long time" 3
- Continue treatment until regular bowel habits are established, then gradually taper the dose
- Avoid abrupt discontinuation to prevent recurrence of constipation
If lactulose is not effective or poorly tolerated, consider switching to polyethylene glycol (PEG), which has shown superior efficacy in comparative studies 4.