Efficacy and Safety Assessment of a Novel Once-Daily Tablet Formulation of Tramadol : A Randomised, Controlled Study versus Twice-Daily Tramadol in Patients with Osteoarthritis of the Knee.

Objective To compare the 24-hour sustained efficacy and safety of a new tramadolonce-daily formulation ( tramadolOAD) using Contramid® controlled-releasetechnology with a marketed twice-daily formulation ( tramadolBID).