Recent important clinical trials of drugs in osteoporosis.

The antiresorptive therapies (raloxifene, bisphosphonates) commonly used to treat postmenopausal osteoporotic women, reduce the rate of bone remodeling and lowers the fracture rate, but do not increase bone mass. Strontium ranelate has the advantage of also stimulating bone formation. In the Spinal Osteoporosis Intervention study, at the end of 1 year, there was a lower incidence of fractures in the strontium ranelate group than the placebo group (12.2 and 6.4%, placebo and strontium, respectively) and this difference was maintained over the 3 years (32.8 and 20.9%, placebo and strontium, respectively). With the demise of oestrogen treatment for postmenopausal osteoporosis, it is useful that strontium ranelate is emerging as a promising drug in this condition. Secondary osteoporosis (e.g., due to glucocorticoid treatment after cardiac transplantation) tends to be more severe than primary osteoporosis. In a recent trial comparing calcitriol to alendronate after cardiac transplantation, both showed similar abilities to prevent bone loss. As hypercalcaemia is a relatively common adverse effect with calcitriol in the treatment of secondary osteoporosis, requiring monitoring of calcium levels, alendronate is the easier agent to use.