S21_18

Methotrexate and bone mass

M. Mazzantini, O. Di Munno

Sezione di Reumatologia, Dipartimento di Medicina Interna, Università di Pisa, Pisa, Italy.

ABSTRACT
In rheumatoid arthritis (RA), methotrexate (MTX) is probably the most frequently used disease-modifying antirheumatic drug. It is also prescribed for other rheumatic and non-rheumatic diseases, such as juvenile RA, psoriatic arthritis, polymyositis, polymyalgia rheumatica, Horton’s arteritis, inflammatory bowel disease, etc. MTX has been reported to have negative effects on bone: the term "MTX osteopathy" was first used to refer to a clinical syndrome characterized by stress fractures of the lower extremities, diffuse bone pain, and osteoporosis in children who had been placed on long-term maintenance therapy with low-dose MTX for acute lymphoblastic leukemia. Sporadic reports of similar cases among patients taking low-dose MTX for rheumatic diseases, primarily RA, have appeared more recently. Furthermore, in vitro studies have suggested that MTX may exert toxic effects on osteoblasts.
These findings have raised concern about the long-term effects of MTX on bone. However, densitometric studies in RA patients have so far failed to detect decreased bone mass in patients on MTX treatment.

Key words
Bone mass, methotrexate, osteoporosis, stress fractures, rheumatoid arthritis, bone turnover.

Please address correspondence and reprint requests to: Maurizio Mazzantini, MD, Sezione di Reumatologia, Dipartimento di Medicina Interna, Università di Pisa, via Roma no. 67, 56126 Pisa, Italy.