A drug to help restore bowel function in patients with opioid-induced constipation has received FDA approval. Methylnaltrexone bromide (Relistor) is indicated for patients with advanced illness who are receiving palliative care and who haven't responded sufficiently to laxatives.

Opioids interfere with bowel function by decreasing peristalsis. Given by subcutaneous injection, methylnaltrexone counteracts the constipating effects of opioids in the gastrointestinal (GI) tract without affecting opioid-mediated analgesic effects in the central nervous system.

The recommended starting schedule is one dose every other day. Patients should receive no more than one dose every 24 hours. Common adverse reactions include abdominal pain, gas, nausea, dizziness, and diarrhea. The drug is contraindicated in patients with known or suspected mechanical GI obstruction. For more information, visit http://www.relistor.com.