Meloxicam: selective COX-2 inhibition in clinical practice.

Nonsteroidal antiinflammatory drugs (NSAIDs) exert their actions by inhibiting cyclooxygenase (COX). It has recently been postulated that NSAIDs' antiinflammatory efficacy arises from inhibition of the COX-2 isoform of cyclooxygenase, whereas inhibition of the COX-1 isoform produces the troublesome and sometimes serious gastric and renal side effects of NSAIDs. A relatively selective COX-2 inhibitor, such as meloxicam, may combine antiinflammatory efficacy with improved tolerability. In volunteers, indomethacin 75 mg, but not meloxicam 7.5 mg, inhibited renal prostaglandin E2 excretion and platelet aggregation (COX-1 mediated effects). Double-blind, randomized trials in osteoarthritis and rheumatoid arthritis patients have shown equivalent antiinflammatory efficacy among meloxicam 7.5 mg or 15 mg and diclofenac 100 mg, naproxen 750 mg, and piroxicam 20 mg. In a double-blind, placebo-controlled trial, meloxicam (7.5 or 15 mg) caused less endoscopically detected gastrointestinal (GI) damage (Lanza scale) than piroxicam 20 mg. The MELISSA study, a double-blind, randomized, 28-day trial in over 9,000 patients showed that meloxicam 7.5 mg caused statistically less total GI toxicity, dyspepsia, abdominal pain, nausea and vomiting, and diarrhea than diclofenac 100 mg, despite equivalent reductions in pain on movement for each treatment. A global safety analysis of clinical trials, representing over 5,600 patients and comprising 170 and 1,100 patient-years of exposure for meloxicam 7.5 mg and 15 mg, respectively, showed that meloxicam caused less GI toxicity and fewer peptic ulcers and GI bleeds than naproxen, diclofenac, or piroxicam. The renal safety profile and incidence of liver function abnormalities with meloxicam is equivalent to other NSAIDs available for clinical use. In conclusion, relatively selective COX-2 inhibition exemplified by meloxicam may offer effective symptom relief with an improved GI tolerability profile.