Zoledronic acid (Zometa) | Cancer Research UK
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What zoledronic acid is

Zoledronic acid is a drug that can reduce the risk of fractures in cancers affecting the bone, most commonly

  • Myeloma
  • Secondary breast cancer
  • Secondary prostate cancer

It also lowers high levels of calcium in the blood (hypercalcaemia), which can occur with secondary bone cancer.

Zoledronic acid is a type of drug known as a bisphosphonate. It also has the brand name Zometa. 


How zoledronic acid works

Zoledronic acid attaches itself to bone cells and slows down the rate of bone change.


How you have zoledronic acid

Zoledronic acid is a clear liquid. You have it into your bloodstream (intravenously). You can have it through a thin, short tube (a cannula) put into a vein in your arm each time you have treatment. Or you may have it through a central line, a portacath, or a PICC line. These are long, plastic tubes that give the drugs directly into a large vein in your chest. You have the tube put in before or during your course of treatment and it stays in place as long as you need it.

You can read our information about having chemotherapy into a vein.

The drip usually lasts for about 15 minutes, but you may have it over a longer period.

Treatment to prevent bone damage

You have zoledronic acid every 3 to 4 weeks – you may need to take calcium and vitamin D supplements if you are having it regularly.

Treatment to reduce calcium levels

You have zoledronic acid as a single treatment to reduce the calcium levels in your blood.


Tests during treatment

You have blood tests before starting treatment and regularly during your treatment. The tests check your levels of blood cells and other substances in the blood. They also check how well your liver and kidneys are working.


About side effects

We've listed the side effects associated with zoledronic acid. You can use the links to find out more about each side effect. Where there is no link, please go to our information about cancer drug side effects or use the search box at the top of the page.

You may have a few side effects. They 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)

The side effects may be different if you are having zoledronic acid with other medicines.

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.

  • Flu like symptoms, including a fever, chills and headache
  • Low levels of calcium in your blood (hypocalcaemia), causing changes in sensation such as tingling or burning in your lips and tongue – you will have blood tests to check the levels of calcium and other minerals such as potassium, phosphate and magnesium
  • Feeling or being sick – this usually only lasts for a few days and can be controlled with anti sickness medicines
  • Loss of appetite
  • Anaemia (a drop in the number of red blood cells)
  • Red and sore eyes (conjunctivitis) – you may need eye drops to soothe your eyes

Occasional side effects

Between 1 and 10 in every 100 people have one or more of these.

  • Bone pain – this may be worse when you first start treatment and you may need stronger painkillers until it improves
  • Stomach pain occurs in just under 1 in 10 people (10%)
  • Difficulty in sleeping
  • Mood changes – you may feel anxious or agitated while you are having this drug
  • Redness and pain or itching at the injection site
  • Kidney changes – your doctor will take blood tests regularly to check how well your kidneys are working
  • Changes in blood pressure – during treatment, your blood pressure may be lower or higher than usual so your nurse or doctor will check this regularly
  • Changes to your bowels – you may be constipated or have diarrhoea
  • An allergic reaction, causing swelling of the face, mouth and throat and breathlessness – let your doctor or nurse know straight away if you have this
  • Tiredness, drowsiness and dizziness – let your doctor or nurse know if you have this and don't drive or operate machinery
  • Damage to the jawbone (osteonecrosis) can be a side effect of taking bisphosphonates. This usually occurs if they are taken for longer than a year. You need to have a dental check up before you start treatment and tell your dentist that you are having zoledronic acid
  • Chest pain – let your doctor or nurse know if you have this
  • Taste changes
  • A dry mouth
  • An increased risk of getting an infection from a drop in white blood cells – it is harder to fight infections and you can become very ill. You may have headaches, aching muscles, a cough, a sore throat, pain passing urine, or you may feel cold and shivery. If you have a severe infection this can be life threatening. Contact your treatment centre straight away if you have any of these effects or if your temperature goes above 38°C
  • Bruising more easily due to a drop in platelets – you may have nosebleeds, or bleeding gums after brushing your teeth. Or you may have lots of tiny red spots or bruises on your arms or legs (known as petechiae)
  • Trembling
  • Low levels of magnesium and potassium in the blood – let your doctor or nurse know if you have cramping in your arm or leg muscles, tingling or numbness, palpitations (feeling your heart beat irregularly), or feel faint
  • Weight gain
  • Sweating
  • Blurred vision, increased tears, and sensitivity of the eyes to light
  • Suddenly feeling cold
  • Difficulty breathing with wheezing or coughing
  • Skin rashes and itching

Rare side effects

Fewer than 1 in 100 people have these effects.

  • A slow heart beat
  • Confusion
  • A fracture of the thigh bone in people taking zoledronic acid for years – tell your doctor or nurse straight away if you have a sudden pain, weakness or discomfort in your thigh, hip or groin
  • Swollen and painful joints

Important points to remember

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.

Pregnancy and contraception

This drug may harm a baby developing in the womb. It is important not to become pregnant or father a child while you are having treatment and for a few months afterwards. Talk to your doctor or nurse about effective contraception before starting treatment.


Don't breastfeed during this treatment because the drug may come through in the breast milk.


More information on zoledronic acid

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 www.medicines.org.uk.

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 yellowcard.mhra.gov.uk.

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Updated: 8 October 2015