BMA Concise Guide to Medicine & Drugs

Strontium Ranelate

Brand name Protelos

Used in the following combined preparations None


Drug group Drug for bone disorders

Overdose danger rating Low

Dependence rating Low

Prescription needed Yes

Available as generic No


Strontium ranelate is used to treat severe osteoporosis to reduce the risk of fractures. The active ingredient is derived from a naturally occurring element, strontium, which acts on cells in the bone to increase bone formation and reduce bone resorption, leading to a rebalance of bone turnover in favour of bone formation. Because strontium ranelate has been associated with heart disorders, it is used, under specialist supervision, only for those with severe osteoporosis for whom there are no suitable alternative treatments. Apart from the risk of heart disorders and a small increase in the risk of deep vein thrombosis (blood clots in the legs and lungs), strontium ranelate generally causes few adverse reactions in those who are prescribed the drug. Very rarely, some people may develop a serious allergic reaction to the drug which may affect other organs in the body.


Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.

How taken/used Granules dissolved in water.

Frequency and timing of doses Once daily, usually at night.

Adult dosage range 2g daily.

Onset of effect 3–5 hours. Beneficial effects may take several months to be felt.

Duration of action Up to a week.

Diet advice Food, milk, milk products, and calcium reduce absorption of strontium ranelate. You should take the drug at bedtime or between meals and allow at least 2 hours before or after food, milk, or milk products or calcium supplements.

Storage Keep in original container below 30ºC out of the reach of children. Protect from light.

Missed dose Take the next dose at the time it is due. Do not take a double dose to make up for a missed dose.

Stopping the drug Do not stop the drug without consulting your doctor. Stopping the drug may lead to a worsening of the underlying condition.

Exceeding the dose An occasional unintentional extra dose is unlikely to cause problems. If a large overdose has been taken, notify your doctor.


In general, those prescribed strontium ranelate experience few adverse effects. The most common are nausea and diarrhoea, which often settle with continued use, headache, and drowsiness. Discuss with your doctor if these are severe or persist. Rarely, it may cause swelling or pain in the leg; if so, you should contact your doctor. Very rarely, it may cause a serious allergic reaction. If you develop a rash, fever, or swollen glands, you should stop taking the drug and contact your doctor immediately. Long-term use of the drug has been associated with heart disorders (see Prolonged use).


Tetracycline and quinolone antibiotics (e.g. tetracycline and ciprofloxacin) Strontium ranelate may reduce absorption of these drugs. It should be stopped when taking a course of these antibiotics.

Antacids and products containing calcium, magnesium, or aluminium These can reduce the absorption of strontium ranelate so should be given at least 2 hours before or after the drug.


Be sure to tell your doctor if:

· You have ever had a previous adverse reaction to strontium ranelate.

· You have long-term kidney problems.

· You have or have had heart problems.

· You are being treated or have been treated for blood clots in your leg or lungs.

· You are confined to bed or are due to have surgery.

· You have phenylketonuria.

· You are taking other medicines.

Pregnancy Not prescribed. In women, the drug is used only after the menopause.

Breast-feeding Not prescribed. In women, the drug is used only after the menopause.

Infants and children Not prescribed. The drug is for use in postmenopausal women only.

Over 60 No special problems.

Driving and hazardous work No specific problems.

Alcohol No special problems.


The long-term safety of strontium ranelate is uncertain, especially regarding the risk of heart disorders. For this reason, it is prescribed only under specialist supervision and when there are no suitable alternatives.

Monitoring Blood and other tests may be carried out to monitor your bone density. Strontium ranelate can interfere with the blood tests used to measure calcium level.