Treatment of opioid-induced constipation in hospice patients with methylnaltrexone

Abstract

8279 Background: Methylnaltrexone (MNTX) is a selective opioid-receptor antagonist that does not cross the blood-brain barrier in humans. It has the potential to counteract the debilitating peripheral side effects of narcotic pain therapy without interruption of centrally-mediated analgesia or precipitation of withdrawal. MNTX is being developed for the treatment of opioid-induced constipation (OIC) which is refractory to laxatives and stool softeners. Methods: The activity and tolerability of MNTX were investigated in a series of phase 1 and 2 clinical trials. Normal subjects as well as patients receiving chronic opioids were treated with various doses of MNTX administered via intravenous and subcutaneous routes. Relief of OIC by subcutaneous MNTX was evaluated in hospice patients in phase 2 trials. Results: Results from completed studies demonstrate that MNTX was generally well tolerated and significantly reduced or prevented OIC, urinary retention, as well as other peripheral side effects of opioids. S...