Onset of analgesic effect and plasma levels of controlled-release tramadol (Tramadol Contramid once-a-day) 200-mg tablets in patients with acute low back pain.

Background And Aims: Tramadol hydrochloride, a centrally acting, synthetic analgesic, has been available in Europe since 1977 in a variety of formulations and in the United States since 1995. Its clinical efficacy was established in a variety of painful conditions (cance rpain, neuropathic pain, and osteoarthritis). Nonetheless, little published data exist regarding the relationship between analgesic onset and minimum therapeutic plasma levels.

A comparison of the analgesic efficacy of Tramadol Contramid OAD versus placebo in patients with pain due to osteoarthritis.

One thousand twenty-eight (1,028) patients with pain due to osteoarthritis (OA) of the knee were enrolled in this multicenter, randomized, double-blind, parallel study designed to assess the analgesic efficacy and safety of Tramadol Contramid OAD compared to placebo. An open-label phase was followed by a double-blind phase, in which a total of 646 patients were randomized to double-blind treatment with placebo or Tramadol Contramid OAD. Patients were titrated to their optimal dose (200mg or 300 mg), which was maintained for 12 weeks.