How do you administer Miralax (polyethylene glycol)?

How to Administer Miralax (Polyethylene Glycol)

For adults and children 17 years and older, mix one heaping tablespoon (17 g) of Miralax powder in 4-8 ounces of any beverage and drink once daily. 1

Standard Administration Instructions

• For adults and children 17 years and older:

  • Measure one heaping tablespoon (17 g) or one packet of Miralax powder 1
  • Dissolve completely in 4-8 ounces of any beverage (cold, hot, or room temperature) 1
  • Drink once daily 1
  • Ensure the powder is fully dissolved before drinking; do not drink if there are any clumps 1

• For constipation management in palliative care:

  • Standard dose is one capful (17 g) in 8 oz water twice daily 2
  • Goal is to achieve one non-forced bowel movement every 1-2 days 2

Special Considerations

• Do not combine with starch-based thickeners used for difficult swallowing 1
• For children under 17 years of age, consult a doctor for appropriate dosing 1
• In children with dysfunctional elimination, the average effective dose is 0.63 g/kg 3
• For severe constipation in adults, higher doses may be needed:
  • 68 g (4 capfuls) has been shown to be effective for rapid relief within 24 hours 4
  • This higher dose produced bowel movements at an average of 14.8 hours after administration 4

Duration of Treatment

• Do not use for more than 7 days without medical supervision 1
• For chronic constipation management, polyethylene glycol has shown to be effective and safe for longer-term use under medical supervision 2, 5

Efficacy and Monitoring

• Polyethylene glycol likely increases complete spontaneous bowel movements by approximately 2.9 per week compared to placebo 2
• Monitor for:
  • Frequency of bowel movements (target: one non-forced bowel movement every 1-2 days) 2
  • Stool consistency (should become softer) 2
  • Side effects such as bloating, abdominal cramps, or diarrhea 2

Potential Side Effects

• Common side effects include abdominal distension, loose stool, flatulence, and nausea 2
• Diarrhea may occur, especially with higher doses 3, 4
• Unlike some other laxatives, polyethylene glycol does not cause significant electrolyte disturbances when used at recommended doses 6

Contraindications

• Do not use in patients with bowel obstruction or ileus 2
• Use caution in patients with suspected bowel impaction - rule out obstruction before use 2

Important Clinical Pearls

• Polyethylene glycol is more effective than fiber supplements for chronic constipation 2
• Unlike stimulant laxatives, patients do not develop tolerance to polyethylene glycol 2
• For bowel preparation before colonoscopy, standard polyethylene glycol with electrolytes (GoLytely) is more effective than Miralax alone 7
• Polyethylene glycol without electrolytes (Miralax) may be more palatable than versions with electrolytes 6