Opioids
Use of Methylnaltrexone for the Treatment of Opioid-Induced Constipation in Critical Care Patients
Gastrointestinal dysmotility and constipation are common problems in critical care patients. The majority of critical care patients are treated with opioids, which inhibit gastrointestinal (GI) motility and lead to adverse outcomes. We reasoned that methylnaltrexone (MNTX), a peripheral opioid antagonist approved for the treatment of opioid-induced constipation in patients with advanced illness receiving palliative care when response to laxative therapy has not been sufficient, could improve GI function in critically ill patients.Development of Peripheral Opioid Antagonists: New Insights Into Opioid Effects
The recent approval by the US Food and Drug Administration of 2 medications—methylnaltrexone and alvimopan—introduces a new class of therapeutic entities to clinicians. These peripherally acting μ-opioid receptor antagonists selectively reverse opioid actions mediated by receptors outside the central nervous system, while preserving centrally mediated analgesia. Methylnaltrexone, administered subcutaneously, has been approved in the United States, Europe, and Canada. In the United States, it is indicated for the treatment of opioid-induced constipation in patients with advanced illness (eg, cancer, AIDS) who are receiving palliative care, when response to laxative therapy has not been sufficient.
