CONTINUOUS AND CYCLICAL CLODRONATE THERAPIES AND BONE-DENSITY IN POSTMENOPAUSAL BONE LOSS

Objective: To evaluate the effectiveness of different clodronate regim ens in postmenopausal osteoporosis. Methods: In groups of 20, 60 women were randomly assigned to one of three treatments: oral calcium, 1000 mg/day; oral calcium plus oral clodronate, 400 mg/day; oral calcium p lus oral clodronate, 400 mg/day for 30 days, followed by a 60-day peri od of calcium supplement alone. This last regimen was repeated four ti mes in the 12-month study period. Results: Patients who received calci um alone showed a decline in spinal bone mass, both after 6 and 12 mon ths (P < .03 and P < .005, respectively); femoral density in this grou p also decreased after 6 and 12 months (P < .002 and P < .05, respecti vely). On the other hand, both clodronate-treated groups had increased levels of lumbar bone mass compared with controls, both after 6 and 1 2 months of therapy. However, at the end of the study, patients treate d with cyclical clodronate had higher spinal bone mass compared with t hose treated continuously (3.32 +/- 0.71 versus 0.43 +/- 0.89%, P < .0 2). After 6 months, femoral bone density was significantly higher both in subjects treated with clodronate, both cyclically and continuously (P < .01), compared with controls. Continuous clodronate treatment re sulted in a clear fall in biochemical indices of bone resorption, toge ther with a consequent decrease in osteocalcin at 6 (P < .02) and 12 m onths (P < .003) and a significant increase in parathyroid hormone aft er 12 months (P < .001) of therapy. Conclusion: Over-year treatment wi th clodronate induces a gain in bone mass, especially in the spine. Th e continuous regimen does not result in any further benefit in lumbar greater suppression of bone turnover.