A double blind study of antrafenine, naproxen and placebo in osteoarthrosis.

Antrafenine, a new non-narcotic analgesic, has been compared at a dose of 600 mg/day to naproxen 500 mg/day and placebo in a double blind three way cross-over study on 36 patients with osteoarthrosis of the hip and/or knee. There was significant improvement with both active drugs. There was no significant difference between the two active drugs. Patients' preference at the end of the study was antrafenine 7, naproxen 10, placebo 2, no preference 9.3 patients withdrew because of concomitant illness; 2 patients withdrew because of lack of efficacy in the placebo period; 3 patients failed to attend clinic. Antrafenine is more efficacious than placebo in the treatment of osteoarthrosis of the hip and/or knee, and at the doses tested, is of comparable potency to naproxen.