Sodium clodronate (Bonefos, Clasteon) | Cancer Research UK
Cancer Research UK on Google+ Cancer Research UK on Facebook Cancer Research UK on Twitter

Sodium clodronate (Bonefos, Clasteon)

Nurse and patients talking about cancer

This page tells you about the bisphosphonate drug sodium clodronate and its specific side effects. There is information about


What sodium clodronate is

Sodium clodronate is a type of bisphosphonate drug. Doctors use it to treat the symptoms of cancers that affect the bones. The cancers most commonly treated are myeloma and secondary breast cancer.


How sodium clodronate works

Cancer that has spread to the bones encourages the breakdown of too much bone. This weakens the bones, making fractures more likely. It can also cause pain and release calcium from the bone cells into the blood. Sodium clodronate helps to slow down the breakdown of bone by the cancer cells.

You may have sodium clodronate for the following reasons

  • To lower high blood calcium levels (hypercalcaemia)
  • To strengthen weak areas of bone (osteolytic lesions)
  • To reduce bone pain due to cancers that have spread to the bone

You may also have it to maintain calcium levels after a one off drip of a bisphosphonate drug.


How you have sodium clodronate

You may have sodium clodronate as tablets or capsules. They are also called Bonefos or Clasteon. You usually take them once a day at the same time each day.

You take the tablets or capsules with water. You need to take them on an empty stomach, at least 1 or 2 hours before or an hour after you have a meal, drink, or other medicines. Other foods or medicines (especially milk) can stop sodium clodronate being absorbed. 

If you forget a dose take it as soon as possible. But if it is nearly time for your next dose, skip the missed dose and just take the next dose at the usual time. Do not take a double dose.

If you accidentally take too much sodium clodronate tell your doctor straight away.

It is very important that you take tablets according to the instructions your doctor or pharmacist gives you. You should take the right dose, not more or less. And never stop taking a cancer drug without talking to your specialist first.

We've listed the side effects associated with sodium clodronate below. You may have a few of them. You can use the links to find out more about each side effect. Where there is no link, please go to our cancer drug side effects section or use the search box at the top of the page.

Tell your doctor or nurse straight away if any of the side effects get severe.


Common side effects

More than 10 in every 100 people have one or more of these.

  • Diarrhoea
  • Feeling or being sick is usually due to the tablets or capsules irritating your stomach – dividing the dose and taking half in the morning and half in the evening may help to reduce sickness
  • Low levels of calcium in your blood (hypocalcaemia) – you will have blood tests to check the levels of calcium and other minerals such as potassium, phosphate and magnesium. A low calcium level can cause changes in sensation so you may have tingling or burning in your lips and tongue. Let your doctor or nurse know if you have this
  • Liver changes that are very mild and unlikely to cause symptoms – they will almost certainly go back to normal when treatment is finished, but you will have regular blood tests to check how well your liver is working

Occasional side effects

Between 1 and 10 in every 100 people have a rash, which may be itchy.


Rare side effects

Fewer than 1 in 100 people have these.

  • Kidney changes – you will have regular blood tests to check how well your kidneys are working
  • Breathlessness and a cough
  • Damage to the jaw bone (osteonecrosis) – this can be a side effect of taking bisphosphonates for longer than a year. Have a dental check up before you start treatment and tell your dentist that you are having sodium clodronate. You may need to stop having sodium clodronate if you need dental treatment. It is important to clean your teeth regularly and have regular dental checks
  • Red or peeling skin
  • Fractures at the top of the thigh bone (femur) – let your doctor or nurse know if you have any pain in the top of the leg, your groin, or your hip
  • Changes in lung tissue may lead to a cough, breathlessness or difficulty breathing – tell your doctor or nurse if you have any of these effects
  • Severe bone, joint or muscle pain may occur some months after starting to take sodium clodronate

Important points to remember

The side effects above may be mild or more severe. A side effect may get better or worse through your course of treatment, or more side effects may develop as the course goes on. This depends on

  • How many times you've had the drug before
  • Your general health
  • The amount of the drug you have (the dose)
  • Other drugs you are having 

Coping with side effects

Talk to your doctor, pharmacist or nurse about all your side effects so they can help you manage them. They can give you advice or reassure you. Your nurse will give you a contact number to ring if you have any questions or problems. If in doubt, call them.

Other medicines

Tell your doctor about any other medicines you are taking, including vitamins, herbal supplements and over the counter remedies. Some drugs can react together.

Drink plenty

It is important to drink plenty of fluids while having sodium clodronate treatment so that you don't get dehydrated.

Pregnancy and contraception

Clodronate can harm a developing baby so you should not become pregnant or father a child while taking this drug. Discuss contraception with your doctor or nurse before you start your treatment if you think you or your partner could become pregnant.


Do not breastfeed while taking sodium clodronate because the drug may come through in the breast milk.


Related information

On this website you can read about 



Secondary breast cancer

There is general information about bisphosphonates in the cancer treatment section.


More information about sodium clodronate

This page does not list all the very rare side effects of this treatment that are very unlikely to affect you. For further information look at the Electronic Medicines Compendium website at

If you have a side effect not mentioned here that you think may be due to this treatment you can report it to the Medicines Health and Regulatory Authority (MHRA) at

Rate this page:
Submit rating


Rated 4 out of 5 based on 5 votes
Rate this page
Rate this page for no comments box
Please enter feedback to continue submitting
Send feedback
Question about cancer? Contact our information nurse team

No Error

Updated: 5 February 2014