Naloxone inhibits the anti-diarrhoeal activity of loperamide.
1 Subcutaneous prostaglandin E2 (2.5 mg/kg) produces profuse diarrhoea in fed rats. 2 Pretreatment of rats with subcutaneous loperamide (1.0 mg/kg) completely prevents prostaglandin-induced diarrhoea. If naloxone is administered prior to loperamide injections the activity of the antidiarrhoeal compound is completely destroyed. 3 These data provide strong evidence that the antidiarrhoeal activity of loperamide is mediated via the opiate receptor.
D000818:Animals; D003967:Diarrhea / Q000139:chemically induced; D008139:Loperamide / Q000037:antagonists & inhibitors*; D008297:Male; D009270:Naloxone / Q000494:pharmacology*; D010880:Piperidines / Q000037:antagonists & inhibitors*; D011458:Prostaglandins E / Q000037:antagonists & inhibitors / Q000494:pharmacology; D051381:Rats
D010880:Piperidines; D011458:Prostaglandins E; D009270:Naloxone; D008139:Loperamide