What are the first-line laxatives for pediatric patients?

First-Line Laxatives for Pediatric Patients

Polyethylene glycol (PEG) is the first-line laxative of choice for pediatric constipation due to its superior efficacy, safety profile, and palatability. 1, 2

Recommended First-Line Options

Polyethylene Glycol (PEG)

• Dosing:
  • Initial dose: 0.8-1 g/kg/day (range 0.27-1.42 g/kg/day) 3
  • For infants and young children: 2.5-10 mL in divided doses 2
  • For older children: PEG 3350 at 17-20 g daily mixed in 4-8 ounces of liquid 1
• Advantages:
  • Highly effective with dose-dependent action 2
  • Well-tolerated with excellent safety profile 4
  • Better palatability compared to other laxatives 5
  • No loss of efficacy with long-term use 5

Osmotic Laxatives (Alternative First-Line)

• Lactulose:
  • Dosing: For infants and young children: 2.5-10 mL in divided doses; for older children: 40-90 mL total daily dose 6
  • Reduce dose if diarrhea occurs; discontinue if diarrhea persists 6
• Advantages:
  • Effective for improving stool consistency 7
  • Draws water into the intestine to hydrate and soften stool 7

Treatment Algorithm

1. Initial Assessment:

   • Confirm diagnosis of functional constipation (less than 3 bowel movements per week, hard stools, straining)
   • Rule out warning signs requiring further evaluation (blood in stool, failure to thrive, severe abdominal distension)

2. First-Line Treatment:

   • Start with PEG 3350 at 0.8 g/kg/day 3
   • Adjust dose every 3 days to achieve 2 soft stools per day 3
   • Target stool consistency: soft but formed (not watery)

3. If PEG is unavailable or not tolerated:

   • Use lactulose at age-appropriate dosing 6
   • For infants: 2.5-10 mL daily in divided doses
   • For older children: 40-90 mL total daily dose

4. Adjunctive Measures:

   • Increase dietary fiber (20-25g daily) gradually over several weeks 1
   • Ensure adequate fluid intake (at least 8 glasses of water daily) 1
   • Encourage regular physical activity within the child's capabilities 1

Special Considerations

For Infants

• Clear liquids for 24 hours with normal saline enema (10 mL/kg) may be sufficient for infants with normal or frequent bowel movements 7
• PEG microenemas have shown non-inferiority to oral PEG in young children (6-48 months) and may be an alternative when oral administration is challenging 8

For Disimpaction

• Higher doses of PEG may be required initially for fecal disimpaction before maintenance therapy 2
• PEG is recommended for both disimpaction and maintenance treatment according to international guidelines 2

Monitoring and Follow-Up

• Monitor stool frequency and consistency
• Assess for side effects (typically minor with PEG)
• In patients predisposed to water and electrolyte imbalances, consider monitoring serum electrolytes 2
• Adjust dosing to maintain 2-3 soft stools daily 3

Common Pitfalls to Avoid

1. Inadequate dosing: Many treatment failures occur due to insufficient laxative doses. Titrate to effect rather than using fixed doses.

2. Premature discontinuation: Long-term treatment is often necessary. Abrupt discontinuation can lead to relapse.

3. Overreliance on stimulant laxatives: While effective, stimulants like bisacodyl and senna should generally be second-line options after osmotic laxatives in children.

4. Ignoring behavioral aspects: Address any toilet avoidance behaviors or withholding patterns, particularly in toilet-training children.

5. Using sodium phosphate preparations in young children: The American Gastroenterological Association notes that sodium phosphate should not be used in children younger than 12 years due to risk of electrolyte abnormalities 7.

PEG has revolutionized the treatment of pediatric constipation, with studies consistently showing excellent efficacy, safety, and patient acceptance, making it the current gold standard first-line laxative for children 4.