Browser does not support script.
Skip to main content
search here
Macmillan and Cancerbackup merged in 2008. Together we provide free, high quality information for people affected by cancer through our publications, website and phone service. Find out more|.
Find out how we produce our information|
This information is about a drug called clodronate that can be used when cancer has spread to the bone|.
Clodronate belongs to a group of drugs called bisphosphonates|. Bisphosphonates are commonly used to treat bone thinning (osteoporosis). In certain situations, they can help protect your bones against some of the effects of secondary bone cancer, such as pain and weakness. Secondary bone cancer occurs when the original (primary) cancer spreads to form a secondary cancer (metastasis) in the bone.
Clodronate is often given alongside other cancer treatments. As well as being used in some types of secondary bone cancer, it has been shown to be effective in people with myeloma| (a cancer of the plasma cell in the blood). It is also used to lower a raised calcium level in the blood.
As a result of secondary bone cancer, calcium, which helps strengthen the bones, can be lost from the damaged bone and seep into the bloodstream. A raised level of calcium in the blood is known as hypercalcaemia. This can cause symptoms such as feeling or being sick (nausea or vomiting), tiredness|, irritability and sometimes confusion. Clodronate can help reduce high levels of calcium.
Secondary cancer in the bones may make them weak, and in some situations they may break (fracture). Clodronate can help re-strengthen the bone and reduce the risk of fractures.
Cancer can affect the bones in different ways, and clodronate is not helpful for all cancers that affect the bones. Your doctor or specialist nurse can tell you if it would be helpful for you.
In normal bone, two types of cells called osteoclasts and osteoblasts work together constantly to shape, rebuild and strengthen existing bone:
Myeloma and some secondary bone cancers can produce chemicals that make the osteoclasts work harder. This means that more bone is destroyed than rebuilt, which leads to weakening of the affected bone. This can cause pain and means that the bone can fracture or break more easily.
Clodronate targets areas of bone where the osteoclast activity is high. It helps bring the balance of osteoclast and osteoblast activity back to normal by reducing the activity of the osteoclasts. This can reduce pain and help strengthen the bone. It also means that less calcium will be lost from the bones.
Clodronate is given as tablets or capsules, usually taken once or twice a day. It is recommended that you take the tablets or capsules in the morning and evening, and not within one or two hours of eating, having a milky drink or taking other medicines. This is because it is harder for the drug to be absorbed into the bloodstream, which can make it less effective. Avoid taking clodronate with mineral supplements, such as multi-minerals, for the same reason.
Your nurse, doctor or pharmacist will explain how you should take your tablets.
If you are having clodronate to lower your calcium level, you may be given tablets or capsules to maintain your calcium at a normal level. If your calcium level is very high, you may also be given a single dose of a bisphosphonate drug into the vein (intravenously) to bring it down faster.
If you are having clodronate to reduce pain or strengthen your bones, then you may need to take it for as long as it seems to be working.
Some people have very few side effects while others may experience more. The side effects described below won't affect everyone who has clodronate and may be different if you are having more than one drug.
We have outlined the most common side effects but haven't included those that are rare and therefore unlikely to affect you. If you notice any effects that aren't listed below, discuss them with your doctor or nurse.
Sometimes, clodronate can cause diarrhoea|. This can usually be controlled with medicine, but let your doctor know if it is severe or continues.
This is uncommon and usually mild. It can be controlled with anti-sickness (anti-emetic)| medication.
This is rare and usually only temporary. Your doctor will carry out regular blood tests to monitor the level of calcium in your blood.
Clodronate can sometimes affect how your kidneys work. This does not usually cause any symptoms, and the effects are generally mild. Your doctor will monitor how well your kidneys are working during your treatment by doing regular blood tests.
A rare side effect of clodronate is a condition called osteonecrosis of the jaw. This is when healthy bone tissue in the jaw becomes damaged and dies. Gum disease, problems with your dentures and some dental treatments, such as having a tooth removed, can increase the risk of this. So before you start taking the drug, you'll be advised to have a full dental check-up.
During treatment with bisphosphonates, it's very important to look after your teeth by brushing them regularly and having routine dental check-ups. Always let your dentist know that you're taking bisphosphonates. Some of the symptoms of osteonecrosis can include pain, swelling, redness of the gums, loose teeth or a feeling of numbness or heaviness in your jaw. Tell your cancer specialist and dentist straightaway if you have any of these symptoms.
This section has been compiled using information from a number of reliable sources, including:
For answers, support or just a chat, call the Macmillan Support Line free (Monday to Friday, 9am-8pm)
If you have any questions about cancer, need support or just want someone to talk to, ask Macmillan.