Modification of the behavioural effects of ethanol by nifedipine.
Nifedipine (10.0 mg/kg) was administered to mice together with graded doses of ethanol (0, 2.5, 3.0, 3.5, 4.0 and 4.5 g/kg), and activity measured over a 2-hr period following administration. Low ethanol doses increased activity, whereas the highest dose decreased it. By itself, nifedipine had no effect on activity, but when combined with ethanol it produced a consistent decrease in comparison with ethanol alone. This occurred irrespective of whether the ethanol dose alone increased or decreased activity. These results demonstrate a clear interaction between nifedipine and ethanol which cannot be characterized as simple potentiation or antagonism. Time-course data showed that the effects of nifedipine were apparent within 10-20 min of drug administration, but, in the case of the highest ethanol dose, increased toward the end of the 2-hr period. Retardation of the development of acute tolerance may contribute to the interaction between ethanol and nifedipine.
White
J M
JM
Department of Clinical and Experimental Pharmacology, University of Adelaide, Australia.
Smith
A M
AM
D000328:Adult; D000818:Animals; D002121:Calcium Channel Blockers / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D000431:Ethanol / Q000008:administration & dosage*; D006801:Humans; D008124:Locomotion / Q000187:drug effects*; D008297:Male; D009543:Nifedipine / Q000008:administration & dosage*; D051381:Rats; D013997:Time Factors
D002121:Calcium Channel Blockers; D000431:Ethanol; D009543:Nifedipine