R. Mcmahon, A. Ridolfo, H. W. Culp
Jul 1, 1971
Citations
1
Influential Citations
79
Citations
Quality indicators
Journal
Toxicology and applied pharmacology
Abstract
Abstract Propoxyphene N -demethylation is the primary initial metabolic step in the rat. Ester hydrolysis also occurs. A large number of metabolic end products of propoxyphene are formed. They are mainly excreted in bile as conjugates. Metabolism in the dog appears to be less complex than in the rat. Norpropoxyphene and one other metabolite predominate, although several minor metabolites are present. The human differs from the rat and dog in that propoxyphene metabolites are eliminated primarily in urine rather than bile. Only one major metabolite, unconjugated norpropoxyphene, is present. This is readily isolated and characterized as the alkaline rearrangement product norpropoxyphene amide. Norpropoxyphene concentrations in human plasma are higher than those of propoxyphene. The half-life of norpropoxyphene is also substantially longer than that of propoxyphene.