Tramadol for osteoarthritis: a systematic review and metaanalysis.

OBJECTIVE: Tramadol is increasingly used for the treatment of osteoarthritis (OA) because it does not produce gastrointestinal bleeding or renal problems and does not affect articular cartilage. We sought to determine the analgesic effectiveness, the effect on physical function, the duration of benefit, and the safety of oral tramadol in people with OA.
METHODS: We searched the Cochrane Central Register of Controlled Trials (Central), Medline, Embase, and Lilacs databases up to August 2005. We included randomized controlled trials (RCT) that evaluated the effect of tramadol or tramadol plus paracetamol on pain levels and/or physical function. No language restriction was applied.
RESULTS: We included 11 RCT with a total of 1019 participants who received tramadol or tramadol/paracetamol and 920 participants who received placebo or active control. Participants who received tramadol reported (1) less pain [-8.5 units on a 0-100 scale; (95% CI -12.0 to -5.0)], a 12% relative decrease in pain intensity; (2) higher degree of global improvement: one of every 6 individuals taking tramadol or tramadol/paracetamol exhibited at least moderate global improvement (95% CI 4 to 9); and (3) improvement in stiffness and function, an 8.5% relative improvement in Western Ontario and McMaster University Osteoarthritis Index score, than patients who received placebo. In terms of adverse events, one of every 5 participants who received tramadol or tramadol/paracetamol experienced minor adverse events and one of every eight stopped taking the medication because of adverse events (95% CI 7 to 12) compared to participants who received placebo.
CONCLUSION: Tramadol or tramadol/paracetamol decreases pain intensity, produces symptom relief, and improves function in patients with OA, but these benefits are small.