SAN ANTONIO — The older generation osteoporosis drug, strontium ranelate, is receiving renewed attention as a result of a metaanalysis showing that it reduces fracture rates in postmenopausal women as well as bisphosphonates do.
Like bisphosphonates, strontium ranelate inhibits bone resorption but also increases bone formation, a combination that improves bone density and bone mass, Jean-Yves Reginster, M.D., said at the annual meeting of the American College of Rheumatology.
In one of the reports, strontium ranelate for 3 years reduced vertebral fracture risk by 41%, and increased lumbar-spine bone density by 14% and femoral neck density by 8%, relative to placebo. The 1,649 subjects were osteoporotic women who had previously had a vertebral fracture (N. Engl. J. Med. 2004;350:459-68).
Dr. Reginster's metaanalysis of that study and a similar investigation confirmed strontium ranelate's effectiveness in preventing hip and vertebral fractures, even in the frail elderly.
In that analysis, which involved more than 7,000 postmenopausal women, the risk of vertebral fracture during a 3-year period was reduced by 32% in 1,488 women aged 80 years or older, and nonvertebral fracture risk was reduced by 31%. Among the 1,977 women who were older than 77 years and had a baseline bone mineral density T-score of -3 or less, the hip fracture rate was reduced by 36% relative to placebo.
The drug's efficacy in elderly patients shows it was building bone mass, not just density, Dr. Reginster of the University of Liege (Belgium) said at a press briefing.
Bisphosphonates tend not to be so effective in the very elderly, he added.
Among the patients in both studies who had not previously had a vertebral fracture—about 2,500 patients—the vertebral fracture rate was reduced by 48% relative to placebo. Similar risk reductions are seen with bisphosphonate treatment (47% for alendronate and 49% for risedronate).
Diarrhea was the only side effect that was significantly more associated with the study drug, occurring in 6% of those patients.
Like a bisphosphonate, strontium ranelate is taken on a fasting stomach. The dosage used in the studies was 2 g daily. Participants also took calcium and vitamin D supplements.