Treatment of Antipsychotic-Induced Constipation

Introduction to Constipation Management

The American Gastroenterological Association and the American College of Gastroenterology give polyethylene glycol (PEG) a strong recommendation with moderate certainty of evidence for chronic constipation 4
PEG increases complete spontaneous bowel movements by 2.90 per week compared to placebo 4
The National Comprehensive Cancer Network (NCCN) guidelines recommend stimulant laxatives, such as sennosides, for constipation caused by anticholinergic drugs, including many antipsychotics 1, 5

Polyethylene glycol 3350 (Miralax) is recommended at a dose of 17 grams (one heaping tablespoon) dissolved in 8 oz of water twice daily 2, 4
Sennosides alone are recommended at a dose of 2-3 tablets twice to three times daily, titrated to effect 1, 3
The goal of treatment is to achieve one non-forced bowel movement every 1-2 days 1, 2, 3

The NCCN guidelines recommend discontinuing any non-essential constipating medications if possible 1, 5
Patients should begin PEG 3350 at 17 grams twice daily with 8 oz water each dose, and add sennosides starting at 2 tablets twice daily 1, 2, 3, 4
Ensure adequate fluid intake throughout the day 1, 2
Titrate sennosides up to 8-12 tablets per day maximum if needed, and assess response after 2-4 days 8

If constipation persists, consider adding bisacodyl 10-15 mg orally 2-3 times daily or as a rectal suppository 1, 5, 7
Magnesium-based products, such as magnesium hydroxide 30-60 mL daily or magnesium citrate 8 oz daily, may also be considered 1, 5, 7

Do not add psyllium or other fiber supplements for antipsychotic-induced constipation, as they are ineffective and may worsen symptoms 2, 3
Patients do not develop tolerance to constipation from antipsychotics, so ongoing prophylactic treatment is necessary 2, 3