title: Methylnaltrexone, a novel peripheral opioid receptor antagonist for the treatment of opioid side effects.
abstract: Methylnaltrexone is an investigational peripheral opioid receptor antagonist, a quaternary derivative of naltrexone. Methylnaltrexone has greater polarity and lower lipid solubility, thus it does not cross the blood-brain barrier in humans. Methylnaltrexone offers the therapeutic potential to block or reverse the undesired side effects of opioids that are mediated by receptors located in the periphery (e.g., in the gastrointestinal tract), without affecting analgesia or precipitating the opioid withdrawal symptoms that are predominantly mediated by receptors in the CNS. This article reviews preclinical studies and clinical opioid bowel dysfunction trial data, and briefly discusses other potential roles of this compound in clinical practice.
authors.affiliation: Pritzker School of Medicine, Department of Anesthesia & Critical Care, The University of Chicago, 5841 S. Maryland Avenue, MC 4028, Chicago, IL 60637, USA. cyuan@uchicago.edu
authors.forename: Chun-Su
authors.initials: CS
authors.lastname: Yuan
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Israel
mesh_terms: D000701:Analgesics, Opioid / Q000009:adverse effects*; D000818:Animals; D006801:Humans; D009271:Naltrexone / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use; D009292:Narcotic Antagonists / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use; D011957:Receptors, Opioid / Q000502:physiology
chemical_list: D000701:Analgesics, Opioid; D009292:Narcotic Antagonists; D000644:Quaternary Ammonium Compounds; D011957:Receptors, Opioid; C032257:methylnaltrexone; D009271:Naltrexone