Polyethylene Glycol (PEG) is the First-Line Laxative for Pediatric Constipation
Polyethylene glycol (PEG) is the recommended first-line laxative for pediatric patients with constipation due to its superior efficacy, excellent safety profile, and better tolerability compared to other laxatives. 1
Evidence for PEG in Pediatric Constipation
- PEG has demonstrated significantly higher success rates (56%) compared to lactulose (29%) in treating pediatric constipation, with fewer side effects and better patient tolerance 2
- The recommended initial dose of PEG for pediatric patients is 0.4 g/kg/day, which provides optimal efficacy while minimizing side effects 3
- PEG works as an osmotic laxative that draws water into the intestine to soften stool and increase bowel movements, with minimal systemic absorption 1
- Clinical studies show PEG effectively increases defecation frequency and decreases encopresis frequency in children with constipation 2
Dosing Guidelines for PEG in Pediatric Patients
- For children under 18 months: The mean effective maintenance dose is 0.78 g/kg/day (range 0.26-1.26 g/kg/day) 4
- For children over 18 months: Start with 0.4 g/kg/day and titrate based on response 3
- For older children: The standard initial dose is 17g daily, which can be adjusted based on symptom response 5
- PEG can be used safely for extended periods with no maximum dose limit, allowing for flexibility in treatment 5
Advantages of PEG Over Other Laxatives
- PEG causes fewer side effects than lactulose, with children reporting less abdominal pain, straining, and pain during defecation 2
- Unlike magnesium-based laxatives, PEG does not pose a risk of electrolyte imbalances, making it safer for long-term use 1
- PEG is more effective than lactulose, which has a latency of 2-3 days before onset of effect and commonly causes bloating 1
- PEG is relatively inexpensive ($10-$45 monthly) compared to prescription constipation medications 5
Clinical Considerations
- Ensure adequate hydration when using PEG, as with all osmotic laxatives 1
- Common side effects are generally mild and include bloating, abdominal discomfort, and cramping 1
- Some children may report bad taste as a side effect of PEG more often than with lactulose 2
- For severe constipation or fecal impaction, higher initial doses may be needed, followed by maintenance therapy 6
Alternative Options
- If PEG is not available or not tolerated, lactulose can be considered as an alternative osmotic laxative 7
- For pediatric patients, lactulose dosing ranges from 2.5-10 mL in divided doses for infants and 40-90 mL total daily dose for older children and adolescents 7
- However, lactulose is associated with more side effects and lower success rates compared to PEG in pediatric constipation 2
PEG has consistently demonstrated superior efficacy and safety in pediatric patients, making it the laxative of first choice for childhood constipation 2.