Skeletal benefits of alendronate: 7-year treatment of postmenopausal osteoporotic women

We report here the second 2-yr extension of a clinical trial among postmeno pausal women; 235 women continued blinded treatment with 5 or 10 mg alendro nate daily, and 115 women who had been treated with alendronate for 5 yr we re switched to blinded placebo. Continuous treatment with alendronate (10 m g daily) for 7 yr increased lumbar spine bone mineral density (BMD) by 11.4 % compared to baseline. After the initial 18 months, each additional year o f treatment through yr 7 increased spine BMD by 0.8% for the IO-mg dose and 0.6% for the 5-mg dose, with significant increases during yr 6-7. Previous ly reported increases in BMD at other skeletal sites and decreases in bioch emical markers of bone turnover remained stable during yr 6-7. Among women previously taking alendronate for 5 yr who were switched to placebo, there was no significant decline in BMD at the spine or hip, whereas small, but s ignificant, decreases in BMD at the forearm and total body and small increa ses in biochemical markers were observed. The safety and tolerability profi les were similar to those of placebo. This is the largest published long-te rm study of antiresorptive therapy. Our findings indicate that long-term al endronate treatment is well, tolerated and effective for 7 yr. Increases in spinal BMD continue for at least 7 yr, and other skeletal benefits are mai ntained. Discontinuation does not lead to accelerated bone loss, but contin uous treatment yields better skeletal benefits than shorter treatment.