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What is strontium ranelate and how does it work?

Strontium ranelate, which is called Protelos in the UK, is the first in a new class of osteoporosis drug treatments. Other drug treatments for osteoporosis work by suppressing the action of the osteoclasts which break down bone or by stimulating the action of the osteoblasts which build bone. Strontium ranelate is the first treatment which works by performing both these functions.


Does this mean strontium ranelate is better than other treatments for osteoporosis?

The aim of any treatment for osteoporosis is to reduce the risk of broken bones. There have not been any studies comparing the effectiveness of strontium ranelate in reducing the risk of such fractures with other treatments for osteoporosis. However, it appears to be similar in reducing the risk of fractures in the spine and there is also some recent evidence from published research that strontium reduces the risk of non vertebral fractures including those of the hip.


Who can take it?

Strontium ranelate is licensed for post menopausal women with osteoporosis to reduce the risk of fractures in the spine and hip.



What about men?

At present, the studies into the effectiveness of strontium ranelate have only been conducted on post menopausal women. Servier, the French drug company who manufacture strontium ranelate, are planning to look at the effects in men so may increase the licence to include this group in the future.


How is it taken?

Strontium ranelate is a 2g sachet of tasteless powder to be mixed in a glass of water. It should be taken once daily preferably at bedtime, at least two hours after eating and at least two hours before any food or drink, other than water. This is because the absorption of the drug may be affected if food or drink other than water is present in the stomach.


Can I take any other tablets (such as pain killers and sleeping tablets) at the same time as strontium ranelate?


There are a wide range of medications that will not affect the absorption of strontium ranelate. Most sleeping tablets and pain killers will fall into this category but if you are unsure about medication you are taking, you may like to discuss this further with your doctor or pharmacist.


What are the side effects?

Unlike bisphosphonates  (alendronate  (Fosamax or alendronic acid), risedronate (Actonel) and cyclical etidronate (Didronel PMO)), strontium ranelate causes very few digestive problems and there is also no need to remain upright after taking it. In the trials, strontium ranelate was well tolerated without any major side effects. Those side effects reported were mild and short lived, the most common being nausea and diarrhoea, which were generally reported at the beginning of treatment. There is a slight increase in the risk of blood clots associated with strontium ranelate. Although this side effect is rare, people who are already prone to blood clots may not be advised to use this treatment.

A rare type of severe allergic reaction to strontium ranelate has been reported. This is a serious hypersensitivity reaction, which can also occur with a number of other drugs. It usually develops within three - six weeks of starting strontium ranelate but generally resolves on drug withdrawal and steroid treatment. Although rare, anyone who develops a skin rash, fever, swollen glands or mouth ulcers whilst taking strontium ranelate, is advised to stop the treatment immediately and seek advice from their doctor.


How do I know that strontium ranelate is working?

The aim of any treatment is to reduce the risk of broken bones, so if fractures are not occurring, this may indicate that a treatment is working. Sometimes, bone density scanning is used to assess the effectiveness of osteoporosis treatment. As the presence of strontium may cause bone to appear denser than it actually is, scan results will have to be adjusted to allow for this.


Do I need to take extra calcium?

It is recommended that you obtain an adequate calcium intake as part of a well balanced diet.

If you have difficulties obtaining adequate calcium from your diet, a calcium supplement may be prescribed by your doctor. (All patients participating in the strontium ranelate research trials had an adequate calcium intake). If you are using a calcium supplement, you must not take it in the two hours before or two hours after you have taken the strontium ranelate.

Factors that can help to maintain healthy bones are a well balanced diet with adequate calcium rich foods, regular weight bearing exercise, avoiding smoking and keeping alcohol consumption within the recommended limits.

To obtain other NOS publications and Information Sheets, go to www.nos.org.uk or telephone

0808 800 0035

To contact the NOS osteoporosis nurses, telephone the NOS Helpline on 0808 800 0035 or e-mail them on nurses@nos.org.uk

For regular updates on osteoporosis, join the NOS on-line today www.nos.org.uk

or telephone 01761 473117 / 473119 to speak to one of our Membership Co-ordinators.

The information given in this Information Sheet has been prepared in consultation with

members of the NOS Scientific Advisory Group (SAG) as general advice on the subject.