Antitussive effects of Ca2+ channel antagonists.
The effects of Ca2+ channel antagonists on the capsaicin-induced cough reflex in guinea pigs were studied. Intraperitoneal injection of nifedipine, verapamil and flunarizine in doses that ranged from 0.3 to 3.0 mg/kg decreased the number of coughs in a dose-dependent manner. These Ca2+ channel antagonists exhibited antitussive effects in the following order of potency: flunarizine = verapamil greater than nifedipine. Pretreatment with a low dose of nifedipine (0.3 mg/kg), which by itself had no significant effect on the number of coughs, markedly increased the antitussive effects of morphine, dihydrocodeine and dextromethorphan. These data suggest that Ca2+ channels play an important role in the regulation of the cough reflex.
Kamei
J
J
Department of Pharmacology, School of Pharmacy, Hoshi University, Tokyo, Japan.
Kasuya
Y
Y
D000818:Animals; D000996:Antitussive Agents / Q000627:therapeutic use*; D002121:Calcium Channel Blockers / Q000627:therapeutic use*; D002211:Capsaicin; D003061:Codeine / Q000031:analogs & derivatives / Q000627:therapeutic use; D003371:Cough / Q000139:chemically induced / Q000188:drug therapy*; D003915:Dextromethorphan / Q000627:therapeutic use; D004347:Drug Interactions; D004357:Drug Synergism; D005444:Flunarizine / Q000627:therapeutic use; D006168:Guinea Pigs; D008297:Male; D009020:Morphine / Q000627:therapeutic use; D009543:Nifedipine / Q000627:therapeutic use; D014700:Verapamil / Q000627:therapeutic use
D000996:Antitussive Agents; D002121:Calcium Channel Blockers; D003915:Dextromethorphan; D009020:Morphine; D014700:Verapamil; D009543:Nifedipine; C014481:dihydrocodeine; D005444:Flunarizine; D002211:Capsaicin; D003061:Codeine