S-adenosyl methionine (SAMe) versus celecoxib for the treatment of osteoarthritis symptoms: a double-blind cross-over trial. [ISRCTN36233495]

Najm WI, Reinsch S, Hoehler F, Tobis JS, Harvey PW · BMC Musculoskeletal Disorders

In the first month of phase 1 celecoxib reduced pain significantly more than SAMe (p = 0.024); by the second month the two arms no longer differed. Against the trial's own equivalence criterion — a 10-point minimum clinically significant difference — equivalence was met at the end of month 2 and not at the end of month 1: the mean difference on pain today was 9.3 then -0.4, and on pain over the past month 11.6 then 1.6. Most functional health measures improved from baseline in both arms with no separation between them, and isometric joint function improved steadily across the whole study regardless of treatment. Adverse events were reported by 36 subjects during the SAMe period and 46 during the celecoxib period, with no individual event differing significantly.

Population

61 adults with knee osteoarthritis, 56 of whom completed a 16-week double-blind crossover

Intervention

S-adenosylmethionine 1,200 mg daily

Comparator

Celecoxib 200 mg daily

Limitations

Sixty-one patients, no placebo arm, and a crossover design in a condition where both arms improved throughout — which is the pattern a placebo arm exists to interpret. About three quarters of the way through, a routine quality check found the study's SAMe had lost roughly half its potency; the trial was paused for a fresh batch, and the authors' modelled potency effect ran in the expected direction without reaching significance (p = 0.188). Of the subjects who switched from celecoxib to SAMe, 12 of 29 reported pain in that first month against 2 of 24 switching the other way (p = 0.011).