Abstract
Since the mid-eighties, several medications, aiming at the inhibition of bone resorption, have consistently shown their ability to reduce fracture rates, at various skeletal locations, in osteoporotic post-menopausal women. Unfortunately, the diagnosis of osteoporosis is frequently made after the first fracture occurs. At this stage, bone strength has significantly decreased, as a result of low bone mineral density and disrupted bone micro architecture. Medications have now been developed to specifically stimulate bone formation, with the ultimate goal to restore the affected skeleton and to bring back bone biomechanical resistance to a normal level. The peptides from the parathyroid hormone family (1-34 human recombinant fragment or teriparatide and the 1-84 full length hormone) are potent stimulators of bone formation. They both have shown their ability to dramatically reduce vertebral fractures, whereas teriparatide alone has, so far, confirmed this effect on non-spinal events. These peptides were shown to have a carryover effect, with their anti-fracture efficacy (teriparatide) maintained up to 30 months after treatment has been interrupted. However, the prescription of an anti-resorptive agent after withdrawal of teriparatide prevents further bone loss. Strontium ranelate is characterized by a dual mechanism of action, combining an inhibition of bone resorption and a simulation of bone formation. This new chemical entity has been tested in long-term studies which have shown, after 5 years, a reduction of fracture rates at the spine, at non vertebral locations and at the hip (in patients above 74 years old with prevalent low bone density at the femoral neck). Strontium ranelate reduces fractures in patients with or without prevalent vertebral fractures, in osteoporotic patients, in osteopenia and in subjects above the age of 80 years. Development of medications aiming at the restoration of normal bone strength and resistance is one of the most exciting perspectives in the management of post-menopausal osteoporosis.