RESUMEN
<p><b>OBJECTIVE</b>To investigate the effectiveness of alendronate Chinese national product in the prevention and treatment of postmenopausal osteoporosis.</p><p><b>METHODS</b>The 56 postmenopausal women with osteopenia or osteoporosis were randomly divided into two groups: treated with alendronate 10 mg/d (28 cases) orally and placebo (28 cases), for 6 months. All subjects received 600 mg/d of calcium carbonate and vitamin D 1,000 U/d. Bone mineral density (BMD) of the lumbar spine, femoral neck, trochanter and Ward's triangle were measured by dual energy X-ray absorptiometry as well as the markers of bone turnover were analysed at the beginning and the end of the study.</p><p><b>RESULTS</b>The results showed that lumbar spine BMD increased by 5% in the alendronate group (P < 0.01), but decreased in BMD of the lumbar spine and femur in the placebo group (P < 0.05) after 6 months of treatment. In the alendronate group the marker of bone resorption and bone formation were significantly decreased after alendronate therapy. There were no change in placebo group.</p><p><b>CONCLUSIONS</b>Alendronate (Chinese national product) is effective in reducing bone turnover and promoting bone mass of postmenopausal osteoporosis.</p>