Methylnaltrexone vs Naloxegol in the Treatment of Opioid-Induced Constipation

Methylnaltrexone Versus Naloxegol in the Treatment of Opioid-Induced Constipation in the Emergency Department

The purpose of this study is to compare the efficacy of subcutaneous versus oral mu-opioid receptor antagonist therapy in opioid induced constipation that is refractory to other bowel regimens.

Opioid-induced constipation can lead to serious complications, including small bowel obstruction, fecal impaction, and bowel perforation. Not only are the medical complications potentially severe, patient quality of life can also be impacted. Two agents are currently available for opioid-induced constipation - oral and subcutaneous methylnaltrexone and oral naloxegol. Mechanistically, both agents antagonize the peripheral mu-opioid receptor in the gastrointestinal tract to decrease constipation without reversing the systemic analgesic effects of opiates. The literature currently available has evaluated the effectiveness of each agent, not the comparative effectiveness of these agents.

Inclusion Criteria:

• Complaint of opioid-induced constipation refractory to other therapy (enemas, laxatives, stool softeners)
• Age≥18y/o
• Not pregnant or lactating (negative urinary pregnancy test)
• No contraindication to Methylnaltrexone or Naloxegol

Exclusion Criteria:

• Age<18y/o
• Pregnancy or lactation
• Contraindication to Methylnaltrexone or Naloxegol
• Assigned NPO
• Small bowel obstruction