Biophosphonates in reducing fracture risk in osteoporosis
Bisphosphonates are the class of drugs that have been studied for osteoporosis treatment, Paget’s disease, osteolytic metastases, hypercalcemia malignancy and some childhood skeletal diseases. Worldwide, millions of people, especially post-menopausal women, are now taking bisphosphonates. Besides the medicinal use, they are also utilized for their chelating metal properties, in prosthetic surgery for stabilizing nano-particles and as scintigraphic tracer in many osteo-articular diseases.
Clodronate belongs to this family and was one of the first bisphosphonates to be synthesized and used in the field of medicine. This has been successfully used for treating tumoral osteolysis and for bone localization of multiple myeloma, hypercalcemia malignancy, primary hyperparathyroidism, Paget's disease and algodystrophy. Clodronate has been proved to have an anti-inflammatory and anti-arthritic activity in humans.
It was the first drug used to treat osteoporosis, administered at intervals of 8 or 15 days when there was no consolidated data in literature about its anti-fracture efficacy. This drug has been administrated weekly 100 mg i.m. and after 1–3 years of therapy, bone mass increase of 4% at vertebral level and of about 3% at femoral level were noticed.
Clodronate doses of 800 mg/day per os and 100 mg i.m./week are substantially equivalent, because the oral absorption is about 1.9%. Moreover, it is possible to predict a differentiated use of clodronate doses to the fracture risk and to the severity of pain symptoms.
These clinical findings revealed that clodronate is an effective therapy to increase bone density and reduce risk of fractures, as it is well tolerated, safe and has a good therapeutic adherence, cost effectiveness in patients with fracture risk over 7% identified by algorithmth (FRAX). Clodronate is a potential alternative to other established therapies for osteoporosis.