1. What is sodium clodronate?
2. Who might be offered sodium clodronate?
3. How is it taken?
4. How long will I take sodium clodronate for?
5. Side effects of sodium clodronate
6. Further support

1. What is sodium clodronate?

Sodium clodronate is a tablet that’s given to reduce the risk of breast cancer spreading to the bones and other parts of the body.

It belongs to a group of drugs called bisphosphonates. These drugs slow down or prevent bone damage.

Sodium clodronate is also used to treat breast cancer that has spread to the bone

The following information is for women who are taking it to reduce the risk of breast cancer spreading.

2. Who might be offered sodium clodronate?

Sodium clodronate is suitable for women who have been through the menopause (post-menopausal women). It can be used regardless of whether the menopause happened naturally or because of breast cancer treatment.

You may be offered sodium clodronate if you are post-menopausal and have had treatment for invasive breast cancer that has spread to the lymph nodes under the arm.

It may also be considered if you have invasive breast cancer that has not spread to the lymph nodes.

3. How is it taken?

Sodium clodronate tablets are taken once a day.

You will usually be advised to take your tablets in the morning with a glass of water before eating.

You should not have anything to eat or drink (apart from water) for the next hour. You should not take any other tablets during this time.

You should also stay sitting or standing for one hour after taking them to avoid any irritation to the oesophagus (gullet).

4. How long will I take sodium clodronate for?

You will usually be advised to take sodium clodronate for two to three years.

5. Side effects of sodium clodronate?

Like any drug sodium clodronate can cause side effects. Everyone reacts differently to drugs and some people have more side effects than others.

If you’re taking other drugs while having sodium clodronate, you may also experience side effects from these and it’s sometimes difficult to know which drug causes which side effects.

If you have any questions about side effects, whether they are listed here or not, talk to your treatment team.

Common side effects

Nausea (feeling sick) or vomiting (being sick)

This is usually mild. Anti-sickness drugs can be prescribed to relieve it.


This is usually mild. Anti-diarrhoea medication can be prescribed to help control this. 

Contact your treatment team if you have four or more episodes of diarrhoea within 24 hours. 

Drink plenty of fluids to avoid getting dehydrated.

Low calcium levels in the blood

Sodium clodronate can cause calcium levels in the blood to drop too low. This is called hypocalcaemia. You’ll have regular blood tests to check the calcium levels. 

Early symptoms of low calcium levels include tingling around the mouth and lips and in the hands and feet. Let your treatment team know if you experience any of these. 

Your treatment team may recommend calcium and vitamin D supplements. 

Less common side effects

Allergic reaction

Sodium clodronate can cause an allergic reaction. If you become breathless or start to develop an itchy rash let your doctor know straight away.


Sodium clodronate can cause some of the jaw bone to lose its blood supply and die. This is called osteonecrosis of the jaw (ONJ). It’s an uncommon but serious side effect of sodium clodronate.

Symptoms include:

  • lasting jaw pain
  • loose teeth
  • swelling, redness or ulcers on the gums

Let your treatment team and dentist know straight away if you have any of these symptoms. 

ONJ is hard to treat so trying to prevent it is very important. Good dental hygiene can help reduce the risk of developing it. This includes brushing your teeth and flossing, making sure dentures fit well and having regular dental check-ups. 

See your dentist for a check-up before starting treatment with sodium clodronate. Let them know you’ll be taking sodium clodronate and speak to your treatment team if your dentist recommends any treatment before starting or while taking sodium clodronate.

In rare cases osteonecrosis can affect the ear. If you have any ear pain, discharge from your ear or an ear infection while taking sodium clodronate let your treatment team know.


Although it’s rare, sodium clodronate can cause the femur (the large bone in the upper leg) to fracture. It’s not fully understood why this happens and it’s more common in people who have been taking sodium clodronate for a long time.

If you have lasting pain in your thigh, hip or groin, let your treatment team know.

Effects on the kidneys

Sodium clodronate can affect the way the kidneys work. You may have blood tests to monitor this.

6. Further support

If you would like any further information and support about any aspect of breast cancer or just want to talk things through, you can speak to one of our experts by calling our free Helpline on 0808 800 6000.

Last reviewed: April 2019
Next planned review begins 2021

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