Efficacy and safety of 12 weeks of osteoarthritic pain therapy with once-daily tramadol (Tramadol Contramid OAD).

This placebo-controlled study examined the analgesic efficacy, safety, and clinical benefit of Tramadol Contramid OAD, a once-daily formulation with both immediate- and extended-release components. Five hundred and fifty-two patients with moderate to severe pain due to osteoarthritis (OA) of the knee were randomized into this multicenter, double-blind, parallel arm study. After randomization to Tramadol Contramid OAD 100, 200, or 300 mg, or to placebo, patients' dose was titrated to the fixed randomized dose and maintained for 12 weeks.