A multicentre, randomised, double-blind study to compare the efficacy and tolerability of dexketoprofen trometamol versus diclofenac in the symptomatic treatment of knee osteoarthritis

Background: Dexketoprofen trometamol (DKP.TRIS) is the tromethamine salt of dexketoprofen, the S-enantiomer responsible for the pharmacological activi ty of ketoprofen. DKP.TRIS has rapid absorption and onset of action in pain relief. Objective: To compare the efficacy and tolerability of DKP.TRIS and diclofe nac, a nonsteroidal anti-inflammatory drug widely accepted as reference the rapy for symptomatic treatment of osteoarthritis, in patients with chronic pain due to knee osteoarthritis. Design: This was a multicentre, randomised, comparative, double-blind study . Methods: Radiological evidence of osteoarthritis, shown by the presence of Kellgren grade 2 to 4 changes, was required. Patients were evaluated before and after a washout period of 7 to 14 days and after 1 and 2 weeks of trea tment with DKP.TRIS 25mg three times daily orally or diclofenac 50mg three times daily orally. Primary end-points were reduction of pain measured on a visual analogue scale (VAS, 0 to 100mm) and disability measured by the Leq uesne index of severity for knee osteoarthritis (ISK). Tolerability was eva luated by laboratory parameters and frequency and nature of adverse events. Results: Of 117 patients recruited to the study, 115 were treated (61 with DKP.TRIS, 54 with diclofenac) and 99 (54/45) completed the 2-week treatment period. Patient characteristics were homogenous between groups. Pain measu red on the VAS decreased by 43% from 61.7 +/- 18.5mm (mean +/- SD) at basel ine to 34.7 +/- 22.3mm at the end of treatment with DKP.TRIS compared with a 29% decrease from 62.1 +/- 22..7mm to 40.6 +/- 22.2mm for diclofenac [p = 0.027; 95% confidence interval (CI) for the difference between treatments: 1.7, 27.9]. Median [SK scores improved from 11 (range 9 to 12 to 8 (6 to 1 0) in the DKP.TRIS group versus 10.75 (9 to 12.5) to 8.5 (6 to 10.5) in the diclofenac group. There were no group differences for secondary end-points . Adverse events were comparable overall between groups. Conclusion: Oral DKP.TRIS 25 mg three times daily is at least as effective as diclofenac 50mg three times daily for the short term treatment of pain i n patients with osteoarthritis of the knee.