BLOCKADE OF MORPHINE-INDUCED HINDLIMB MYOCLONIC SEIZURES IN MICE BY KETAMINE

Morphine administration can lead to a variety of side-effects, includi ng myoclonus. In an animal model, high morphine doses given intratheca lly elicit hindlimb myoclonic seizures which are not influenced by tra ditional opioid receptor antagonists, such as naloxone. Ketamine preve nts this seizure-like activity in a dose-dependent manner. The respons e is stereoselective, with S-ketamine far more potent than R-ketamine. A competitive NMDA antagonist, NPC17742, also prevents the seizures, although less potently than ketamine. Dextromethorphan has limited act ivity in this model, while haloperidol and pentothal are without any e ffect. Copyright (C) 1997 Elsevier Science Inc.