[Diclofenac vs nimesulide in arthrosis. Plasma levels and clinical efficacy]

Diclofenac and nimesulide are non-steroidal antiinflammatory agents advocated for use in painful and inflammatory rheumatic and certain non rheumatic conditions. In Uruguay, these drugs are administered in doses of 100 mg and 200 mg once a day, respectively. Diclofenac is an effective and safe analgesic and antiinflammatory drug. There are scarce data available on the pharmacokinetic profile of nimesulide. These facts encouraged us to undertake the present study on clinical efficacy, tolerance and pharmacokinetics of nimesulide, controlled with sustained release diclofenac. Twenty patients with osteoarthritis, stage II-III, according to a clinical-radiological evaluation, were selected for the study. Patients were assigned at random to treatment A (Voltaren sustained release, 100 mg) or B (Nodo regular formulation, 200 mg) once a day. A double blind study with active drug and controlled parallel groups was designed. After a washout period of one week patients were treated with active medication during 84 days, and clinical controls every 14 days ensued. Experienced rheumatologists assessed pain and other clinical symptoms. Blood samples were drawn on days 7, 49 and 91 of the study, ten hours after the morning dose, and plasma diclofenac and nimesulide concentrations were measured. On day 7 and 91, blood counts and biochemical laboratory studies were performed (namely, hemoglobin, RBC, WBC, leucocyte differential count, platelet count, alkaline phosphatase, ASAT, ALAT, creatinine, etc.) Already two weeks after the study had begun, significant improvements in clinical parameters assessed were seen for both treatments. A trend to accumulation of diclofenac and nimesulide along the three months of treatment was observed.(ABSTRACT TRUNCATED AT 250 WORDS)