What is Strontium Ranelate?
Strontium ranelate is a patented form of strontium that is well studied and currently approved for the treatment of osteoporosis in most of Europe, but is not yet approved in the United States. The strontium ranelate molecule binds two atoms of strontium that readily dissolve in water and can be absorbed into the body. Strontium ranelate is marketed as a medicinal product by the French company Servier under the brand name Protelos.
How Does Strontium Ranelate Affect Bones?
Relatively small doses of strontium in the form of strontium ranelate significantly reduce fracture risk and increase bone mineral density in postmenopausal women with osteoporosis. The usual dose of strontium ranelate is two grams. This provides about 700 mg of strontium. Two major phase 3 studies have demonstrated the safety and effectiveness of strontium ranelate at this dose.The first study, called the Spinal Osteoporosis Therapeutic Intervention (SOTI) study evaluated the effect of strontium ranelate on the risk of vertebral fractures in over 1600 postmenopausal women with osteoporosis. Published in the New England Journal of Medicine, the study results indicated that the women treated with strontium ranelate had a 49%reduced risk of vertebral fractures during the first year of treatment and a 41% reduced risk over a three year period when compared to the placebo group.
The second study, called the Treatment of Peripheral Osteoporosis Study (TROPOS), studied the effects of strontium ranelate treatment in over 5000 postmenopausal women with osteoporosis. Over a three year period, the risk of all nonvertebral fractures was reduced by 16%. But, even more impressive, women with the lowest bone mineral density T scores (-3 and less) experienced the greatest benefit with 39% reduced fracture risk when compared to the placebo group. This study also confirmed the results of the SOTI study, showing similar reductions in vertebral fracture risk.
How Does Strontium Ranelate Compare to Other Drug Treatments?
It is difficult to compare the results of various studies using different techniques and types of study participants. But, overall, the strontium ranelate studies have reported increased bone mineral density and reduced fracture risk that is comparable to (and in some cases better than) the common bisphosphonate drugs and hormone therapies.
Does Strontium Ranelate Have any Side Effects or Contraindications?
In the large studies conducted using women with osteoporosis, there was no difference in adverse reactions between the placebo and strontium ranelate groups. For most people, strontium appears to be rather safe in the form of strontium ranelate in a product like Protelos that provides about 700 mg of strontium. However, according to Protelos, individuals with severely impaired kidney function should not take strontium ranelate. Some researchers have expressed concerns about strontium being association with bone mineralization defects in patients undergoing dialysis for renal failure. Since strontium ranelate is used by older women who often have reduced renal function, it may be wise to assure good kidney function prior to using strontium ranelate or strontium supplements.
Can Strontium Treatment be Combined with other Drug Treatments?
To date, your osteoporosis guide has not found any studies combining strontium with other drugs such as the bisphosphonate drugs. At this time, combining strontium ranelate or other forms of strontium with other drug treatments cannot be recommended.
Are Other Strontium Compounds Under Current Study?
The Osteologix Company recently obtained a European patent for the use of strontium malonate in the treatment of cartilage and bone conditions, including osteoporosis. Like strontium ranelate, this is a patentable form of strontium. The malonate component is a normal body metabolite that is utilized by the body as an energy source. Osteologix refers to strontium malonate as NBS-101 and is preparing to conduct phase 2 clinical trials.Sources
Genuis, Stephen J and Gerry K. Schwalfenberg. “Picking a bone with contemporary osteoporosis management: Nutrient strategies to enhance skeletal integrity.” Clinical Nutrition (Epub ahead of print, 2006 October 12).Meunier, Pierre J., et al. “The effects of strontium ranelate on the risk of vertebral fracture in women with postmenopausal osteoporosis.” New England Journal of Medicine 350 (2004):459 - 68.
Comment on Meunier et al.:
D'Haese, Patrick C., Francisco Santacruz, and Marc E. De Broe. “Postmenopausal Osteoporosis and Strontium Ranelate.” New England Journal of Medicine 350 (2004):2001 - 3.
Reginster, Jean-Yves, et al. “Strontium ranelate reduces the risk of nonvertebral fractures in postmenopausal women with osteoporosis: Treatment of Peripheral Osteoporosis (TROPOS) study.” Journal of Clinical Endocrinology and Metabolism 90 (2005):2816 - 22.