opioid induced constipation

• related: GI, constipation

• treatment:

  • first line: stool softeners, bulk laxatives, stimulants, osmotics
  • oral naloxegol: peripherally acting μ-opioid receptor antagonist
  • stop current laxative before starting naloxegol, can readd back after 3 days
  • oral naldemedine and subcutaneous methylnaltrexone.

Patients with opioid-induced constipation can be managed initially by increasing fluid and dietary fiber intake and physical activity.  Pharmacotherapy with daily senna-docusate or an osmotic laxative (eg, polyethylene glycol, lactulose) may also be effective.

Those who have refractory constipation despite these measures can significantly improve with subcutaneous methylnaltrexone, a peripherally acting opioid antagonist that does not cross the blood-brain barrier and does not cause opiate withdrawal symptoms.  Methylnaltrexone should be used cautiously in patients with gastrointestinal lesions associated with reduced structural integrity (eg, malignancy, peptic ulcer disease, diverticular disease) as severe abdominal pain and bowel perforation have been observed.  The medication should be discontinued immediately if abdominal pain worsens.