Strontium ranelate: a new paradigm in the treatment of osteoporosis.

In vitro, strontium ranelate increases collagen and non-collagenic protein synthesis by mature osteoblast-enriched cells. The effects of strontium ranelate on bone formation were confirmed as the drug enhanced preosteoblastic cell replication. In the isolated osteoclast, a preincubation of bone slices with strontium ranelate induced a dose-dependent inhibition of the bone resorbing activity of treated rat osteoclast. Strontium ranelate dose-dependently inhibited preosteoclast differentiation. The drug was administered in 160 early postmenopausal women, in a 24-month, double-blind, placebo-controlled, prospective randomised study. At the conclusion of the study, the percentage variation of lumbar bone mineral density (BMD) from baseline was significantly different in the group receiving strontium ranelate 1000 mg/day as compared with placebo (+5.53 versus -0.75%, respectively). Increase in total hip and neck BMD averages were 3.2 and 2.5%, respectively. The effect of strontium ranelate in postmenopausal women with established osteoporosis was assessed during a multinational, prospective, double-blind, randomised, placebo-controlled trial. Strontium ranelate (500, 1000, 2000 mg/day) or placebo were given to 353 Caucasian women with prevalent vertebral osteoporosis. At the conclusion of this 2-year study, the annual increase in lumbar BMD of the group receiving strontium ranelate 2000 mg was 7.3% (p or = 18 months