Safety and efficacy of meloxicam in the treatment of osteoarthritis: a 12-week, double-blind, multiple-dose, placebo-controlled trial. The Meloxicam Osteoarthritis Investigators.

BACKGROUND: Meloxicam (Mobic; Boehringer Ingelheim, Ridgefield, Conn) is an enolic acid derivative of the oxicam group of nonsteroidal anti-inflammatory drugs (NSAIDs) whose mechanism of action may be related to prostaglandin (cyclooxygenase) synthetase inhibition. In previous studies, meloxicam has been found to be safe and effective in the treatment of osteoarthritis (OA) at doses of 7.5 to 15 mg daily. To evaluate a lower dose and a different patient population, we evaluated the efficacy and safety of 3 doses of meloxicam vs placebo and diclofenac for the treatment of OA among patients with symptom exacerbations.

METHODS: In this double-blind, double-dummy, parallel-group, multicenter study, 774 patients with confirmed OA of the hip or knee and a flare were randomized and treated with daily oral administration of meloxicam tablets (at dosages of 3.75, 7.5, or 15 mg/d), diclofenac (100 mg [50 mg twice daily]), or placebo. Treatment was for 12 weeks, with regular assessments for drug safety and efficacy. Safety was assessed by evaluation of adverse events, vital signs, and laboratory data. Primary efficacy variables included the Western Ontario and McMaster University Osteoarthritis (WOMAC) index, the patient's overall assessment of pain, and the patient's and investigator's overall assessment of disease activity.

RESULTS: The incidence of all adverse events was lower at each dosage of meloxicam than for diclofenac but greater than for placebo. However, the incidence of gastrointestinal adverse events and dropout rates because of such events was the same for meloxicam as for placebo and lower than for diclofenac. Meloxicam, at 7.5 and 15 mg/d, and diclofenac were statistically significantly more effective than placebo for all end points, while the 3.75-mg/d dosage of meloxicam did not always reach statistical significance for all end points. Efficacy was evident after 2 weeks of treatment, improved with increasing doses, and was maintained until the end of the trial.

CONCLUSIONS: Meloxicam is a safe and effective medication for the symptomatic treatment of OA. The data support consideration of 7.5 to 15 mg of meloxicam once daily to treat the pain and stiffness of OA, with gastrointestinal tolerability comparable to that of placebo. Arch Intern Med. 2000;160:2947-2954