Safety and efficacy of nabumetone in osteoarthritis: emphasis on gastrointestinal safety

Aim: To compare the efficacy and gastrointestinal (GI) safety of nabumetone with two comparator non-steroidal anti-inflammatory drugs (NSAIDs), diclof enac SR and piroxicam. Methods: Two randomized, double-blind, multicentre, parallel group trials w ere carried out in patients with moderate to severe osteoarthritis of the h ip or knee. During the 6 month treatment phase, the safety and efficacy of nabumetone (1500-2000 mg/day) was compared to diclofenac SR (100 mg/day) or piroxicam (20-30 mg/day). GI safety was evaluated by reviewing all adverse events reported during the trials and presenting all cases of ulcers (comp licated and uncomplicated), as well as other bleeding events that may have been associated with NSAID administration. Results: Most of the efficacy parameters showed no significant differences between the NSAIDs, although diclofenac SR was significantly better than na bumetone in one of 18 efficacy parameters. Nabumetone-treated patients expe rienced significantly fewer ulcer and bleeding events compared to patients treated with the comparator NSAIDs [1.1% (4/348) vs. 4.3% (15/346), P = 0.0 1]. Bleeding events, including outright upper or lower GI bleeding or a sig nificant decline in haemoglobin, occurred in significantly fewer patients t reated with nabumetone than with the comparator NSAIDs [1.1% (4/348) vs. 3. 5% (12/346), P < 0.05]. More importantly, complications associated with eit her ulcers (perforation) or bleeding (leading to hospitalization or withdra wal) occurred in significantly fewer patients receiving nabumetone [0% (0/3 48)] than with comparator NSAIDs [1.4% (5/346), (P < 0.05)]. Conclusion: The results suggest that nabumetone was similar in efficacy by most criteria to diclofenac SR and piroxicam in relieving the symptoms of o steoarthritis; however, nabumetone's GI safety profile was generally superi or to that of both comparator NSAIDs. In the pooled analysis, nabumetone wa s associated with a significantly lower total incidence of ulcers and bleed ing events, and a significantly lower incidence of complications associated with these events.