Risedronate's efficacy: from randomized clinical trials to real clinical practice.

Osteoporosis represents the most common human bone disorder with a large medical and economical burden on the Health Care System. Bisphosphonates are the major drugs used for the treatment of osteoporosis. Differences in their chemical structures and pharmacokinetic actions can explain the different clinical efficacy among these molecules. Risedronate is a potent inhibitor of farnesyl pyrophosphate synthase, but does not bind strongly to mineral; this lower mineral binding may enable risedronate to have a wider distribution in bone. Its antifracture efficacy has been established in several randomized phase III controlled studies that showed its value in the reduction of vertebral, non vertebral and hip fractures. Randomized controlled trials and observational studies demonstrated risedronate efficacy and safety in different subsets of patients, therefore risedronate is configured, among oral therapies currently available for osteoporosis, as a drug of first choice.