Organisms Commons^™

Parent-Metabolite Pharmacokinetic Models For Tramadol – Tests Of Assumptions And Predictions, Sam Holford, Karel Allegaert, Brian J. Anderson, Butch Kukanich, Altamir B. Sousa, Amir Steinman, Bruno Pypendop, Reza Mehvar, Mario Giorgi, Nick Holford

Pharmacy Faculty Articles and Research

Allometric principles were used to discern cross-species differences in (±)-tramadol disposition and formation of its primary analgesic metabolite, (±)-O-desmethyl-tramadol (M1). Species differences in formation of M1 may help predict the analgesic effectiveness of tramadol. Tramadol was administered intravenously by a zero-order (constant infusion) process or rapid bolus dose and racemic concentrations of tramadol and M1 measured. Data were pooled to define differences between species (human, rat, cat, dog, goat, donkey and horse). A two-compartment linear disposition model with first-order elimination was used to describe tramadol and M1 disposition. Slow metabolizers were detected in 6% of the population and tramadol clearance …