Alendronate-induced synovitis.

We describe 7 cases of synovitis or arthritis occurring after commencement of alendronate for treatment of osteoporosis. These were cases from our practice or notified to the New Zealand Pharmacovigilance Centre, Dunedin, New Zealand. There was no evidence of rheumatoid arthritis, pyrophosphate arthropathy, or seronegative arthritis in any patient. Symptoms recurred on rechallenge in 5 of the cases. We conclude alendronate should be considered as a possible cause of synovitis or polyarthritis in patients treated with it in the absence of any other pathology.