CONTINUOUS THERAPY WITH PAMIDRONATE, A POTENT BISPHOSPHONATE, IN POSTMENOPAUSAL OSTEOPOROSIS

There is a need for effective and acceptable therapies for postmenopau sal osteoporosis. The bisphosphonates show promise in this role, but t he effects of the potent bisphosphonates in established osteoporosis h ave not yet been reported. We performed a 2-yr, randomized, double bli nd, placebo-controlled trial of pamidronate (150 mg/day) in 48 postmen opausal osteoporotic women. Bone mineral density of the total body, lu mbar spine, and proximal femur was measured every 6 months by dual ene rgy x-ray absorptiometry. Bone mineral density increased progressively in the total body (1.9 +/- 0.7%; P < 0.01), lumbar spine (7.0 +/- 1.0 %; P < 0.0001), and femoral trochanter (5.4 +/- 1.3%; P < 0.001) in su bjects receiving pamidronate, but did not change significantly in thos e receiving placebo. There were significant decreases in bone density at both the femoral neck (P < 0.02) and Ward's triangle (P < 0.01) in subjects taking placebo, which did not occur in the pamidronate group. The differences between the treatment groups were significant at all sites (0.0001 < P < 0.05) except Ward's triangle. Vertebral fracture r ates were 13/100 patient yr in the pamidronate group and 24/100 patien t yr in those receiving placebo (P = 0.07), and there was a nonsignifi cant trend toward height loss being less in those receiving pamidronat e (P = 0.16). It is concluded that pamidronate is an effective therapy in postmenopausal osteoporosis.