A comparison of the pharmacokinetics,clinical efficacy,and tolerability of once-daily tramadol tablets with normal release tramadol capsules

This report describes a pharmacokinetic study and a clinical study of three different formulations of oral tramadol: once-daily tramadol tablets 150 and 200 mg, and normal release tramadol capsules 50 mg 8-hourly. The randomized, open-label, crossover pharmacokinetic study included 22 subjects. The three treatments showed equivalent mean systemic availability of tramadol. The mean relative systemic availabilities (90% confidence intervals) for the once-daily tablets 150 mg and the once-daily tablets 200 mg versus the normal release capsules were 89.6 (83.3-95.8)% and 90.5 (84.6-96.8)%, respectively. The values for the once-daily tablet 150 mg versus the once-daily tablet 200 mg were 99.0 (92.6-105.9)%. The randomized, double-blind, double-dummy, crossover clinical study included 134 patients with moderate osteoarthritic pain. The three treatments showed similar efficacy; they all reduced patients' pain scores from baseline and there were no significant treatment differences in pain scores during treatment. The three treatments were also well tolerated.