La S-Adenosil Metionina puede ser más eficaz que el colecoxib en el tratamiento de la osteoartritis de rodilla aunque inicialmente su acción es más lenta.
Kathleen A. Wildasin, MA
The dietary supplement S-adenosyl methionine (SAMe) has a «slower onset of action» than does the cyclooxygenase-2 (COX-2) inhibitor celecoxib, but the 2 treatments are equally efficacious in the treatment of symptoms of knee osteoarthritis, new research shows.
To compare the effectiveness of SAMe with celecoxib for pain control, functional health and mood status, isometric joint function, and side effects in treatment of osteoarthritis of the knee, Dr. Wadie I. Najm, University of California-Irvine, Orange, United States, and colleagues conducted a 2-phase prospective, randomised, double-blind study of 61 patients with knee osteoarthritis between September 2000 and September 2002.
Eligibility criteria included age 40 years or older and diagnosis of knee osteoarthritis based on American College of Rheumatology requirements.
The study consisted of two 8-week phases separated by a 1-week washout period.
Thirty patients were randomised to sequence A (SAMe [600 mg twice daily] in phase 1, followed by celecoxib [100 mg twice daily] in phase 2) and 31 patients were randomised to sequence B (celecoxib [100 mg twice daily] in phase 1, followed by SAMe [600 mg twice daily] in phase 2). Twenty-seven patients in sequence A and 29 patients in sequence B completed the study and were analysed for primary outcome.
At the end of the first month of phase 1, patients who received celecoxib showed significant pain reduction from baseline (PS < .01), whereas patients who received SAMe showed "only marginal" pain reduction (PS < .10). During the first month of phase 1, celecoxib was significantly more effective in reducing pain than was SAMe (P= .024); however, by the second month of phase 1, patients in both groups had significant pain improvement from baseline (PS < .01), and no significant difference in pain was observed between groups.
During the first month of phase 2, patients who crossed over from celecoxib to SAMe had noticeably (but not significantly) worse pain than did patients who crossed over from SAMe to celecoxib. By the end of phase 2, no difference in pain was noted between the groups.
The effect of treatment duration and the interaction of duration with treatment type were statistically significant (PS less than or equal to .029).
Both treatment groups showed significant improvement from baseline on measures of work, pain, change in health, and overall health, whereas neither group showed significant change from baseline on measures physical fitness, emotional, and daily activity. Patients who received SAMe showed significant improvement from baseline on quality of life and social support measures (PS less than or equal to .018), whereas such improvement was not observed in patients who received celecoxib.
Significant improvement from baseline on measures of physical function, role physical, bodily pain, and general physical measures was noted in both treatment groups (PS less than or equal to .045), but neither group showed significant change from baseline on measures of mental health, role emotional, social function, general mental, or general health. Patients who received celecoxib showed significant improvement on the vitality measure (]P = .012), but according to the authors, «the magnitude of this effect was quite small.»
Patients in both treatment groups seemed to improve steadily on isometric joint function tests during the course of the study.
Forty-six patients reported adverse events during the celecoxib period, compared with 36 patients during the SAMe period. Most common adverse events included gastrointestinal disorders, anxiety, and dyspepsia.
The authors concluded that the results of the current study confirm those of previous studies regarding the potential role of SAMe in the treatment of knee osteoarthritis, but added that further studies are needed to assess its long-term effectiveness and optimal dose requirement.