What is clodronate?

Clodronate belongs to a group of drugs called bisphosphonates. It can be used to treat:

Clodronate can be given with other cancer treatments.

More information about this treatment

This information is correct at time of publishing. But sometimes the types of cancer this treatment is used for, or treatment side effects, may change between revision dates.

You can talk to your cancer team if you want more detailed information about this treatment. Or visit the electronic Medicines Compendium (eMC) website, which has patient information leaflets (PIL) for individual drugs.

The effect of cancer on the bones

Bones are living and constantly renew themselves. This helps bones keep their strength and shape.

Inside the bones, there are 2 types of bone cell:

  • osteoclasts, which break down and remove old bone
  • osteoblasts, which build new bone.

When we are children and young adults our bones keep getting thicker and stronger. But, as we get older, osteoclasts begin to remove more bone than osteoblasts make. This means our bones slowly become thinner (less dense). In some people, too much bone is lost and they have an in-creased risk of bone fractures.

Myeloma and some secondary bone cancers make chemicals that cause osteoclasts to destroy more bone. This means that more bone is destroyed than rebuilt. The affected bone becomes weak and painful and can break more easily.

Bones contain calcium, which gives them strength. A bone affected by secondary cancer or mye-loma may lose calcium from the bones into the blood. A raised level of calcium in the blood is called hypercalcaemia. This may cause you to have symptoms including:

  • feeling sick (nausea)
  • vomiting
  • tiredness
  • irritability
  • confusion.

How clodronate works

Clodronate reduces the activity of osteoclasts. This can help reduce pain and strengthen the bone.

Clodronate also reduces the amount of calcium lost from the bones. This helps calcium levels in the blood return to normal.

How clodronate is given

Clodronate is taken by mouth as capsules or tablets. You usually take it once or twice a day. Clodronate should be swallowed whole with tap water. Never take it with milk because this reduces the amount of clodronate your body can absorb.

You need to drink plenty of fluids, such as water, while you are taking clodronate treatment.

Always take clodronate tablets exactly as you are told to. This is to make sure they work as well as possible for you. If you are not sure how to take them, check with your doctor or pharmacist. 

If you take clodronate once a day

Take your tablets:

  • in the morning
  • on an empty stomach
  • with a glass of tap water.

After taking clodronate, do not eat, drink (other than tap water) or take any other medicines by mouth for 1 hour.

If you take clodronate twice a day

Take the first dose as above. Take the second dose between meals. Take it at least 2 hours after eating, drinking (other than tap water) or taking any other medicines by mouth.

You should then wait at least 1 hour before eating, drinking (other than tap water) or taking any other medicines by mouth.

Other things to remember about your capsules or tablets

  • Keep them in the original package.
  • Keep them safe and out of sight and reach of children.
  • If your treatment is stopped, return any unused clodronate to the pharmacist.
  • After taking the tablets or capsules, do not lie down. You can sit or stand. This is to avoid you getting tummy pain.

How long clodronate is given for

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 be given a single dose of another bisphosphonate into a vein to bring it down faster.

If you are having clodronate to reduce pain or strengthen your bones, you may continue it for as long as it helps manage the symptoms.

About side effects

We explain the most common side effects of this treatment here. We also include some less common side effects.

You may get some of the side effects we mention, but you are unlikely to get all of them. If you are also having treatment with other cancer drugs, you may have some side effects that we have not listed here. Always tell your doctor, nurse or pharmacist about any side effects you have.

Serious and life-threatening side effects

Some cancer treatments can cause serious side effects. Sometimes, these may be life-threatening. Your doctor, nurse or pharmacist can explain the risk of these side effects to you.

Contact the hospital

Your doctor, nurse or pharmacist will give you 24-hour contact numbers for the hospital. If you feel unwell or need advice, you can call at any time of the day or night. Save these numbers in your phone or keep them somewhere safe.

Dental check-up before treatment

Rarely, this treatment can affect the jawbone. You can read more about this in the “Less common side effects” section below.

Having a healthy mouth and teeth reduces your risk of jaw problems. You usually need a dental check-up to check for any problems before you start treatment.

If you need urgent treatment to lower high calcium levels in your blood, you do not usually need a dental check-up first.

Common side effects

Feeling sick

You may feel sick or be sick (vomit) during treatment. This is usually mild. Your doctor can prescribe anti-sickness tablets to help.

Take the drugs exactly as your nurse or pharmacist tells you to. It is easier to prevent sickness than treat it after it has started.

Diarrhoea

This treatment may cause diarrhoea. Diarrhoea means passing more stools (poo) than is normal for you, or having watery or loose stools. You may also have stomach cramps. If you have a stoma, it may be more active than usual. 

If you are passing loose stools 3 or more times a day and this is not normal for you, contact the hospital as soon as possible on the 24-hour number. Follow the advice they give you about:

  • taking anti-diarrhoea medicines 
  • drinking enough fluids to keep you hydrated and to replace lost salts and minerals
  • any changes to your diet that might help. 

They might also ask you for a specimen of your stool to check for infection.

Sore throat, or indigestion

This may be a sign that the drug is irritating your throat or gullet (the tube between the mouth and the stomach). Tell your doctor before having any more clodronate if:

  • swallowing is painful or difficult
  • you have indigestion that is new or getting worse.

Less common side effects

Numbness or tingling

You may notice numbness or tingling around the mouth, or in the fingers and toes. This may be caused by low levels of calcium in your blood. You will have regular blood tests to check your calcium levels. Contact your doctor straight away if you have these symptoms.

Your doctor may ask you to take calcium and vitamin D supplements, unless you are having this treatment to lower the levels of calcium in your blood. Your doctor will let you know if you need any supplements.

Effect on the kidneys

This treatment can affect how your kidneys work. Drinking plenty of fluids will help your kidneys work well. You will have blood tests to check how well your kidneys are working. Tell your doctor if:

  • you feel generally unwell
  • have any swelling of your face, arms, legs or tummy
  • you notice a change in how often you pass urine (pee).

Pain in the thigh, hip or groin

Sometimes pain in muscles or bones gets worse for a short time when you start taking zoledronic acid. If this happens, your doctor can prescribe painkillers for you until it gets better.

Rarely, people on this treatment develop a break (fracture) in their thigh bone without any obvious cause. Sometimes both thigh bones are affected.

If you have any thigh, hip or groin pain, tell your doctor. Mention that you are taking bisphosphonates. They can arrange tests to check the thigh bones for any signs of weakness or fracture.

Jaw problems

Rarely, this treatment can affect the jawbone. Healthy bone in the jaw becomes damaged and dies. This is called osteonecrosis of the jaw (ONJ). It can cause:

  • pain
  • loosening of the teeth
  • problems with the way the gums heal.

The risk of jaw problems is higher after some types of dental treatment and in people who have gum disease or dentures that do not fit well.

It is important to avoid having any dental treatment that could affect your jawbone when you are having bisphosphonates. This includes having a tooth or root removed or dental implants put in. You can still have fillings, gum treatments or a scale and polish.

To reduce your risk of developing jaw problems your doctor will advise you to:

  • have a full dental check-up before starting treatment
  • look after your teeth and gums during treatment (ask your dentist for advice)
  • tell your dentist you are taking a bisphosphonate before having any dental treatment.

Tell your cancer specialist and dentist straight away if you at any time you develop:

  • pain
  • swelling or redness in your gums
  • numbness or heaviness in your jaw
  • loose teeth.

Ear problems

Very rarely, bones in the outer ear may be affected by this treatment. Always tell your doctor if you have any:

  • ear pain
  • discharge from your ear
  • ear infections.

You should also let them know if you notice any other changes in your ears or hearing.

Allergic reaction

Rarely, clodronate can cause an allergic reaction. If you suddenly feel breathless or develop an itchy rash, seek medical advice immediately.

Red or sore eyes

This treatment may make your eyes feel sore, red and itchy (conjunctivitis). If you have red or sore eyes, your doctor can prescribe eye drops to help treat this. Your pharmacist can tell you how to use the eye drops.

Other information

Lactose

Some clodronate tablets contain lactose. If you have a lactose intolerance, talk to your doctor before you start taking this treatment.

Going into hospital

If you are admitted to hospital for a reason not related to the cancer, it is important to tell the doctors and nurses that you are having treatment with bisphosphonates. You should tell them the name of your cancer specialist. This is so they can talk to them for advice.

Other medicines

Some medicines can affect how this treatment works or be harmful while you are having it. Always tell your cancer doctor, nurse or pharmacist about any drugs you are taking or planning to take, such as: 

Pregnancy

Ask your doctor or pharmacist for advice before taking this medicine if you:

  • are pregnant
  • think you may be pregnant
  • are planning to have a baby.

Breastfeeding

You are advised not to breastfeed while having this treatment, or for some time after treatment ends. This is because the drugs could be passed to the baby through breast milk. 

Your doctor, nurse or pharmacist can give you more information.

Fertility

Some cancer drugs can affect whether you can get pregnant or make someone pregnant. If you are worried about this, it is important to talk with your doctor before you start treatment.

About our information

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert health professionals and people living with cancer.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.

The language we use

We want everyone affected by cancer to feel our information is written for them.

We want our information to be as clear as possible. To do this, we try to:

  • use plain English
  • explain medical words
  • use short sentences
  • use illustrations to explain text
  • structure the information clearly
  • make sure important points are clear.

We use gender-inclusive language and talk to our readers as ‘you’ so that everyone feels included. Where clinically necessary we use the terms ‘men’ and ‘women’ or ‘male’ and ‘female’. For example, we do so when talking about parts of the body or mentioning statistics or research about who is affected.

You can read more about how we produce our information here.

Date reviewed

Reviewed: 01 September 2022
|
Next review: 01 March 2025
Trusted Information Creator - Patient Information Forum
Trusted Information Creator - Patient Information Forum

Our cancer information meets the PIF TICK quality mark.

This means it is easy to use, up-to-date and based on the latest evidence. Learn more about how we produce our information.