Dextromethorphan potentiates the effect of morphine in rats with peripheral neuropathy.
Neuropathic pain responds poorly to opioids. We now report that combination of systemic morphine (2 mg/kg) and dextromethorphan (45 mg/kg), a clinically available antitussive with NMDA-antagonist properties, markedly alleviated mechanical and cold allodynia-like behavior in a rat model of peripheral mononeuropathy. Neither drug produced a significant effect on its own at these doses. The anti-allodynic effect of morphine plus dextromethorphan was reversed by naloxone. The present results suggest that a combination of NMDA-antagonist and opiates might be effective in treating neuropathic pain. Furthermore, the effect of this drug combination is mainly mediated via opioid receptors.
Kauppila
T
T
Karolinska Institute, Department of Medical Laboratory Sciences and Technology, University Hospital, Huddinge, Sweden.
Xu
X J
XJ
Yu
W
W
Wiesenfeld-Hallin
Z
Z
D000701:Analgesics, Opioid / Q000627:therapeutic use*; D000818:Animals; D000996:Antitussive Agents / Q000627:therapeutic use*; D003915:Dextromethorphan / Q000627:therapeutic use*; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D008297:Male; D009020:Morphine / Q000627:therapeutic use*; D009270:Naloxone / Q000627:therapeutic use; D009292:Narcotic Antagonists / Q000627:therapeutic use; D010523:Peripheral Nervous System Diseases / Q000188:drug therapy*; D051381:Rats; D017207:Rats, Sprague-Dawley
D000701:Analgesics, Opioid; D000996:Antitussive Agents; D009292:Narcotic Antagonists; D009270:Naloxone; D003915:Dextromethorphan; D009020:Morphine