Pharmacokinetic interaction of propoxyphene with ethanol

In order to study the effects of ethanol on the pharmacokinetics of propoxyphene, six healthy male volunteers were each given (1) propoxyphene 65 mg p.o. preceded by 1 h by ethanol 0.9 g/kg lean body weight and followed for 7.5 h by ethanol dosed to maintain breath ethanol at 800-1000 mg/l; and (2) propoxyphene 65 mg p.o. with orange juice in the same volume and frequency as ethanol. Ethanol did not induce any significant changes in apparent t 1/2 or Cmax of propoxyphene or norpropoxyphene. The average norpropoxyphene/propoxyphene ratio decreased by a mean 36%.