Contraindications for Miralax (Polyethylene Glycol)
Miralax is contraindicated in patients with kidney disease (except under physician supervision), known bowel obstruction, and polyethylene glycol allergy. 1
Absolute Contraindications
Kidney Disease
- Do not use in patients with kidney disease except under direct physician supervision 1
- While clinical studies show no clinically significant electrolyte changes in patients with normal renal function, the FDA label specifically warns against use in renal impairment 1, 2
- This is particularly important as PEG is an osmotic agent that could theoretically affect fluid and electrolyte balance in compromised kidneys 1
Polyethylene Glycol Allergy
- Absolute contraindication in patients with documented allergy to polyethylene glycol 1
- This is a straightforward hypersensitivity contraindication 1
Bowel Obstruction
- PEG should not be used in patients with paralytic ileus or intestinal obstruction 3
- The ESMO guidelines specifically list intestinal obstruction as a contraindication for osmotic laxatives in the context of advanced cancer 3
Additional High-Risk Situations (Use with Extreme Caution)
Severe Gastrointestinal Conditions
- Avoid in toxic megacolon, severe colitis, or undiagnosed abdominal pain 3
- These conditions require diagnosis before initiating any laxative therapy 3
Recent Surgical or Traumatic Injury
- Contraindicated after recent colorectal or gynecological surgery, anal/rectal trauma, or recent pelvic radiotherapy 3
- The ESMO guidelines emphasize these as contraindications particularly in cancer patients 3
Severe Hematologic Abnormalities
- Use with caution in neutropenia (WBC <0.5 cells/μL) or thrombocytopenia 3
- While this applies more specifically to enemas, osmotic laxatives should be used cautiously in severely immunocompromised patients 3
Important Clinical Pearls
- PEG without electrolytes is generally safe in elderly patients with no clinically significant electrolyte disturbances observed in studies up to 12 months 4, 2
- No dose adjustment needed for elderly patients with normal renal function 4, 2
- Unlike magnesium-based osmotic laxatives, PEG does not cause hypermagnesemia, making it safer in mild-to-moderate renal impairment under supervision 3
- Pre-existing diarrhea is a relative contraindication as PEG would worsen fluid losses 3