Methotrexate osteopathy in rheumatic disease.

OBJECTIVE To determine whether two adults with stress fractures receiving low weekly doses of methotrexate had methotrexate osteopathy. CASE REPORTS Two adult patients developed features consistent with methotrexate osteopathy while receiving low weekly doses of methotrexate. METHODS Iliac crest biopsy samples were taken and bone histomorphometry carried out. RESULTS Symptoms resolved when the methotrexate was discontinued. Bone histology showed changes consistent with osteoblast inhibition by methotrexate. CONCLUSIONS When given in low doses for prolonged periods, methotrexate may have adverse effects on bone, particularly in post-menopausal women.