[A head-to-head comparative study for evaluation of effectiveness among drugs for osteoporosis].

Recent progress in osteoporosis treatment has realized prevention of osteoporotic fractures. However, there is no guideline regarding which agent should be used in an individual patient. In this report, we investigated the effectiveness of several drugs for osteoporosis in a head-to-head comparative study. A total of 776 osteoporotic patients were treated with alendronate (ALN, n=197), etidronate (EHDP, n=199), alfacalcidol (VD3, n=221) and vitamin K2 (K2, n=159). The control group (No, n=266) was followed without treatment. We followed their lumbar bone mineral density (LBMD), bone turnover markers (DPD or NTX or BAP) and presence or absence of incident vertebral fractures for more than 3 years. The mean age was 70 years old. The increase in LBMD after the treatment was highest in ALN treated group (8%) followed by EHDP (6%). VD3 (1-0%) and K2 (-2%). For the change in bone turnover marker after the treatment, ALN and EHDP treated groups showed significant decrease in bone resorption markers but not the VD3 and K2 treated groups. ALN group exhibited more powerful inhibition of fracture rate (Odds ratio 0.305 versus the control, p < 0.01) than the other groups (Odds ratios 0.604-0.668 versus the control p < 0.05). ALN treatment has achieved a wide range effectiveness regardless of fracture risk. On the other hand, EHDP showed significant inhibition of fracture in low risk osteoporosis. VD3 or K2 treated groups did not inhibit new fracture occurrence in low risk osteoporosis but did so in high risk osteoporosis suggesting that those agents may improve bone quality. In conclusion, ALN is thought to be the first line drug in terms of fracture prevention in osteoporosis and the other drugs should be given to the patients who could not recieve ALN.