At what age and minimum weight can a child receive the full adult dose of MiraLAX (polyethylene glycol 3350)?

MiraLAX Dosing by Age and Weight in Children

Children can receive the full adult dose of MiraLAX (17 grams daily) starting at age 15 years, or earlier if they weigh 40 kg or more, regardless of age. 1

Age-Based Threshold for Adult Dosing

• The standard threshold for adult dosing is 15 years of age, a guideline established across multiple therapeutic areas and widely adopted for medication dosing 1
• This 15-year threshold applies to patients with normal weight for their age 1

Weight-Based Override for Younger Children

• Children weighing more than 40 kg should receive adult dosing even if younger than 15 years, as recommended by multiple guideline societies 1
• This weight-based approach ensures appropriate dosing for larger children who have adult-sized body mass 1

Practical Dosing Algorithm

For children 15 years or older:

• Use the full adult dose of 17 grams (one capful) daily, regardless of weight (assuming normal weight for age) 1

For children younger than 15 years:

• If weight is 40 kg or greater: use the full adult dose of 17 grams daily 1
• If weight is less than 40 kg: use weight-based pediatric dosing at approximately 0.8 g/kg/day 2, 3, 4

Pediatric Dosing Evidence for Younger Children

• The effective maintenance dose in children is approximately 0.78-0.84 g/kg/day based on multiple pediatric studies 2, 3, 4
• PEG 3350 has been shown safe and effective in children as young as infants under 18 months, with similar dosing profiles 3, 4
• The dose should be adjusted to achieve 1-2 soft, painless stools per day 2, 3

Important Caveats

• Dosing should be based on ideal body weight rather than actual weight in obese patients, as obesity significantly affects pharmacokinetics 1
• The only significant adverse effect is diarrhea, which resolves with dose reduction 2, 3, 5, 4
• PEG 3350 is well-tolerated with excellent palatability and compliance in pediatric populations 6, 2, 3