IMPACT OF DRUG THERAPY ON BONE METABOLISM

Objective. To determine the effect of zoledronic acid on bone metabolism markers in women with postmenopausal osteoporosis. Subjects and methods. Thirty women with postmenopausal osteoporosis treated with zoledronic acid in dose 5 mg once a year were followed up. The investigators assessed clinical and medical history data, evaluated the gynecological and somatic statuses, and made laboratory and instrumental studies: clinical and biochemical blood tests, general urinalysis, determination of serum bone metabolism markers (B-Crosslaps, osteocalcin), electrocardiography and a therapist’s examination if needed, as well as osteodensitometry. Results. Therapy with zoledronic acid 5 mg once a year was followed by a significant reduction in resorption markers (B-Crosslaps) just following a month, by reaching the lowest values after 3 months and gradually increasing up to the premonopausal level 12 months later. Formation markers decreased to a lesser degree, which was indicative of preserved positive bone-remodeling balance during the therapy. A weak response to therapy was found in 13% of the patients. Conclusion. Zoledronic acid therapy exerts a rapid and potent effect on bone metabolism, mainly by inhibiting the resorption processes. Determination of biochemical markers of bone remodeling permits assessment of an individual patient response to antiresorptive therapy just in the first months after infusion.

osteoporosis, menopause, osteodensitometry, bone mineral density, bone remodeling markers, zoledronic acid