What is Osseor?
Osseor is a drug containing the active substance strontium ranelate, available in 2 g sachets containing a granule for oral suspension.
What is Osseor used for?
Osseor is indicated for the treatment of osteoporosis (a disease that makes bones fragile) in women who have passed menopause to reduce the risk of vertebral and hip fractures.
The medicine can only be obtained with a prescription.
How is Osseor used?
The recommended dose of Osseor is one sachet once a day. The contents of the sachet should be mixed in a glass of water to form a suspension to drink immediately after preparation. Osseor should be taken at least two hours after ingestion of food, milk, dairy products or calcium supplements, preferably at bedtime. Osseor is intended for long-term use. Patients being treated with Osseor should receive supplemental calcium or vitamin D if their dietary intake is insufficient.
How does Osseor work?
Osteoporosis occurs when the old bone tissue, which naturally degenerates, is not replaced with sufficient new tissue. Gradually, the bones become thin and brittle, and the chances of fractures increase accordingly. Osteoporosis is more common in postmenopausal women when levels of the female estrogen hormone, the hormone that helps keep bones healthy, fall.
The active ingredient in Osseor, strontium ranelate, acts on the bone structure. Once the intestine is reached, strontium ranelate releases strontium, a substance that is absorbed by the bones. The mechanism of action of strontium is not entirely known, as far as osteoporosis is concerned, but it reduces bone destruction and stimulates the formation of bone tissue.
What studies have been carried out on Osseor?
Osseor was examined in two large studies involving almost 7, 000 elderly women. Just under a quarter of the patients were over 80 years old. The first study involved 1, 649 women with osteoporosis with previous vertebral fractures, while the second study was carried out on over 5, 000 women with osteoporosis located in the hip and femur region. In both studies the efficacy of Osseor was compared with a placebo (a dummy treatment) and the main measure of effectiveness was the reduction of the risk of a new bone fracture with Osseor. In the first study, this parameter was the number of patients who, over the course of three years, had developed a new vertebral fracture and, in the second study, the parameter was the number of patients who underwent a new peripheral fracture (non vertebral ) due to osteoporosis.
What benefit has Osseor shown during the studies?
In the first study Osseor was effective in reducing the risk of new vertebral fractures by 41% over three years: 21% of the 719 women treated with Osseor developed a new vertebral fracture compared to 33% of 723 patients treated with placebo.
Overall, the results of the second study alone were not sufficient to demonstrate Osseor's benefits in preventing peripheral fractures. However, if only women of 74 years of age or older with a marked fragility of the femur are considered, the results indicate a reduction in the risk of hip fractures when taking Osseor.
Looking at the results of both studies together, fewer women in the Osseor group developed peripheral fractures in parts of the body other than the spine (including the hip) compared to the placebo group (331 out of 3 295 of group treated with Osseor compared to 389 out of 3 256 in the placebo group), thus demonstrating a reduction in the risk of fracture.
What is the risk associated with Osseor?
The most common side effects reported with Osseor (observed in a number of patients between 1 and 10 out of 100) are headache, disturbance of consciousness (fainting), memory loss, nausea, diarrhea, loose stools, dermatitis (skin inflammation ), eczema (scaly rash), venous thromboembolism (blood clots in the veins) and increased levels of creatine kinase (an enzyme present in muscle tissue) in the blood. For the full list of all side effects reported with Osseor, see the Package Leaflet.
Osseor should not be used in people who may be hypersensitive (allergic) to strontium ranelate or any of the other components.
Why has Osseor been approved?
The Committee for Medicinal Products for Human Use (CHMP) decided that Osseor's benefits are greater than its risks for the treatment of osteoporosis in postmenopausal women to reduce the risk of vertebral and hip fractures. The Committee therefore recommended that Osseor be given marketing authorization.
More information on Osseor:
On 21 September 2004, the European Commission issued a marketing authorization for Osseor, valid throughout the European Union, to Les Laboratoires Servier. The marketing authorization was renewed on 21 September 2009.
The full EPAR for Osseor can be found here.
Last update of this summary: 09-2009.
