Double-blind controlled clinical trial of oral S-adenosylmethionine versus piroxicam in knee osteoarthritis.

A double-blind, randomized, 84-day controlled clinical trial was carried out to compare orally administered S-adenosylmethionine (SAMe) (1,200 mg per day) with oral piroxicam therapy (20 mg per day) in the management of unilateral knee osteoarthritis. The ability of each drug to maintain the results achieved at the end of the treatment period was also evaluated during a 56-day follow-up period. Forty-five patients completed the study, 22 in the SAMe group and 23 in the piroxicam group. Both SAMe and piroxicam proved effective in inducing a significant improvement in the total pain score after 28 days of treatment. With regard to the other clinical parameters (i.e., morning stiffness, the distance walked before the onset of pain, active and passive motility), improvement started from about Day 56 in both groups. No significant difference was found between the two treatments in terms of efficacy and tolerability. Patients treated with SAMe maintained clinical improvement achieved at the end of treatment longer than did patients receiving piroxicam.