title: Methylnaltrexone prevents morphine-induced kaolin intake in the rat.
abstract: Opioids are frequently used analgesics, and emesis is a common opioid-induced adverse effect. Methylnaltrexone, a peripheral opioid antagonist, has the potential to block the undesired effects of opioids that are mediated by peripheral receptors while sparing the analgesic effect. We used a rat model of simulated emesis or pica to study if methylnaltrexone decreases morphine induced-kaolin consumption. We observed that after morphine administration, kaolin intake increased significantly compared to intake in the vehicle group, and the increase could be attenuated by ondansetron administration. Methylnaltrexone dose-dependently reduced kaolin ingestion induced by morphine. Morphine and methylnaltrexone did not significantly affect food intake and body weight in the experimental animals. Our data suggest that methylnaltrexone has therapeutic value in treating opioid-induced nausea and vomiting.
authors.affiliation: Department of Anesthesia and Critical Care, University of Chicago, Chicago, IL 60637, USA.
authors.forename: Han H
authors.initials: HH
authors.lastname: Aung
authors.forename: Sangeeta R
authors.initials: SR
authors.lastname: Mehendale
authors.forename: Jing-Tian
authors.initials: JT
authors.lastname: Xie
authors.forename: Jonathan
authors.initials: J
authors.lastname: Moss
authors.forename: Chun-Su
authors.initials: CS
authors.lastname: Yuan
mesh_terms: D000818:Animals; D000932:Antiemetics / Q000008:administration & dosage / Q000494:pharmacology*; D004032:Diet; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D007274:Injections, Intraperitoneal; D007616:Kaolin / Q000008:administration & dosage; D008297:Male; D009020:Morphine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D009271:Naltrexone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology*; D009292:Narcotic Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D017294:Ondansetron / Q000494:pharmacology; D010842:Pica / Q000139:chemically induced / Q000517:prevention & control*; D000644:Quaternary Ammonium Compounds; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000932:Antiemetics; D009292:Narcotic Antagonists; D000644:Quaternary Ammonium Compounds; C032257:methylnaltrexone; D007616:Kaolin; D017294:Ondansetron; D009271:Naltrexone; D009020:Morphine