Treatment of osteoporosis: all the questions we still cannot answer.

Many questions remain with regard to the treatment of osteoporosis. The increase in bone mineral density due to bisphosphonates accounts for only a quarter of their antifracture action. The studies of bone mineral density equivalences that have validated certain modes of administration are therefore not relevant. No comparative study on the same patient cohort has been carried out, and the inclusion criteria of the pilot studies on the drugs currently available are all different. This makes any comparison impossible, and thus, the choice of treatment is subjective. Certain combinations (antiresorptive drugs and anabolic agents) are logical, but no major study is available to validate them. Drugs with a long latency period could interfere with later treatments or allow therapeutic windows, but the data in the literature in support of these hypotheses are scarce. The osteoporotic patient will require treatment for 10 to 30 years, depending on the age at diagnosis, but the available data on the efficacy and nontoxicity of the drugs are based on studies of a duration of only 3 or 5 years.