It’s normal to have lots of questions when you’ve been prescribed a drug like zoledronic acid as part of your treatment for primary breast cancer.
This booklet explains what it is, how it works, who might be offered it and some of the side effects it can cause.
Zoledronic acid is a drug given to reduce the risk of breast cancer coming back and spreading to the bones and other parts of the body.
You may hear it called by its brand name Zometa.
Zoledronic acid belongs to a group of drugs called bisphosphonates. You may hear bisphosphonates called bone-hardening or bone-strengthening treatment.
Bisphosphonates slow down or prevent bone damage.
In all our bodies, whether or not we have cancer, bone tissue breaks down over time and is replaced with new bone tissue. This is a natural process called bone remodelling.
Cancer cells seem to be drawn to areas where bone remodelling is taking place, so secondary breast cancer commonly affects the bones (as well as the lungs, liver and brain).
Bisphosphonates like zoledronic acid work by being absorbed in areas of the body where there is a lot of bone remodelling. This interferes with the remodelling process so may reduce the risk of breast cancer spreading to the bones and elsewhere in the body.
Zoledronic acid is suitable for some women with primary breast cancer. It is given to reduce the risk of breast cancer coming back.
Zoledronic acid is prescribed 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.
The benefits of using zoledronic acid before the menopause are
less clear.
You may be offered zoledronic acid if you are post-menopausal and have had treatment for invasive breast cancer that has spread to the lymph nodes under the arm.
Zoledronic acid may also be considered if your cancer has not spread to the lymph nodes but other factors increase the risk of it returning.
You can read more about the lymph nodes in our booklet
Zoledronic acid is usually started within 3 months of final surgery. If you are having chemotherapy after surgery, you’ll usually start taking zoledronic acid within 2 months of completing chemotherapy.
Zoledronic acid is also prescribed:
The information in this booklet is for women who are having zoledronic acid to reduce the risk of primary breast cancer coming back and spreading.
Zoledronic acid is given as a drip into a vein in your hand or arm (intravenously).
If you had chemotherapy and you have another way of accessing your veins, such as a PICC line or central line, this can be used to give you the drug.
The infusion is usually given in the chemotherapy department of your hospital and takes about 15 minutes.
You may be given an infusion of zoledronic acid every 6 months for 3 years or every 3 months for 2 years.
Like any drug, zoledronic acid can cause side effects. Everyone reacts differently to drugs and some people have more side effects than others. Side effects can usually be managed and those described here will not affect everyone.
This booklet does not list all the possible side effects. If you’re worried about any side effects, regardless of whether they are listed here, talk to your GP or treatment team.
Zoledronic acid can cause flu-like symptoms such as joint and
muscle pain.
Other flu-like effects include fatigue, shivering and fever. These
can last for a few days.
Your treatment team can advise you about taking mild pain relief to help.
This is usually mild. Your treatment team can prescribe you anti-sickness drugs to relieve it.
You may have a headache lasting for a couple of hours to a couple of days after your infusion. Let your treatment team know if you get headaches as they can advise you about taking mild pain relief.
Your eyes may be sore or red for a few days after your treatment. Your treatment team can prescribe eyedrops to relieve this.
Having too few red blood cells is called anaemia.
If you feel particularly tired, breathless or dizzy, let your treatment team know.
You’ll have regular blood tests throughout your treatment.
This is usually mild. Your treatment team can prescribe anti-diarrhoea medication to help control this.
Contact your treatment team if you have 4 or more episodes of diarrhoea within a 24-hour period.
Drink plenty of fluids to avoid getting dehydrated.
Zoledronic acid can cause calcium levels in the blood to drop too low. This is called hypocalcaemia. You’ll have regular blood tests to check your calcium levels.
Early symptoms of hypocalcaemia 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.
Zoledronic acid can sometimes cause an allergic reaction. Let your treatment team know straight away if you become breathless or start to develop an itchy rash.
Zoledronic acid can cause some of the jaw bone to lose its blood supply and die. This is called osteonecrosis of the jaw (ONJ). It’s a rare but serious side effect of zoledronic acid.
Your treatment team will recommend you see a dentist before starting zoledronic acid. If you need any dental work, it’s important to speak to your treatment team, as any dental problems with your teeth or gums must be completely healed before starting treatment.
If you need to have a dental procedure, such as having a tooth removed, you’ll need to wait at least 4 weeks afterwards before starting or restarting zoledronic acid.
If you don’t have a dentist or you are having difficulty
registering with one, let your treatment team know.
When you are having zoledronic acid, you may be given a dental alert card to show a dentist if you develop any symptoms of ONJ. These include:
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.
There is also evidence that people who smoke are more at risk of developing ONJ. Speak to your treatment team or GP if you need support with stopping smoking.
It’s not clear how long the risk of ONJ continues for even once the treatment is completed.
In rare cases osteonecrosis can affect the ear. If you have any ear pain, discharge from your ear or an ear infection while having zoledronic acid, let your treatment team know.
Although it’s rare, zoledronic acid can cause the large bone in the upper leg (femur) to fracture. It’s not fully understood why this happens.
If you have lasting pain in your thigh, hip or groin, let your treatment team know.
Zoledronic acid can affect the way the kidneys work.
You will have blood tests before you start treatment and throughout treatment to monitor this.
If you’d like any further information on zoledronic acid or just want to talk things through, you can call our free helpline on 0808 800 6000.
You never have to face breast cancer alone. Find somebody who understands what you’re going through with Someone Like Me on 0114 263 6490.
You can find out more about our support services online at
We’re Breast Cancer Now, the research and support charity. However you’re experiencing breast cancer, we’re here.
Whoever you are, and whatever your experience of breast cancer, our free services are here. Whether you’re worried about breast cancer, dealing with a diagnosis, working out life with or beyond treatment – or someone you love is.
We support over 290 of the brightest minds in breast cancer research. They’re discovering how to prevent breast cancer, live well with the disease, and save lives. Every day, they get closer to the next breakthrough.
We fight for the best possible treatment, services and care for everyone affected by breast cancer, alongside thousands of dedicated campaigners.
Could you help?
We don’t get any government or NHS funding for our support services or health information. So, we rely on donations and giŁs in wills to make our vital work happen. If you’d like to support us, go to breastcancernow.org/give
ABOuT ThIS BOOkLET
Zoledronic acid for primary breast cancer was wriGen by Breast Cancer Now’s clinical specialists, and reviewed by healthcare professionals and people affected by breast cancer.
For a full list of the sources we used to research it: Email health-info@breastcancernow.org
You can order or download more copies from
We welcome your feedback on this publication:
For a large print, Braille or audio CD version:
Medical disclaimer
We make every effort to ensure that our health information
is accurate and up to date, but it doesn’t replace the information and support from professionals in your healthcare team. So far as is permiGed by law, Breast Cancer Now doesn’t accept liability in relation to the use of any information contained in this publication, or third-party information included or referred to in it.
© Breast Cancer Now, November 2023. All rights reserved BCC238 Edition 2, next planned review 2025
Information you can trust, support you can count on
Whether you’re looking for information about breast cancer or want to speak to someone who understands, you can rely on us.
Call 0808 800 6000 to talk things through
Visit breastcancernow.org for reliable
Breast Cancer Now
Fifth Floor, Ibex House, 42–47 Minories, London EC3N 1DY
Breast Cancer Now is a company limited by guarantee registered in England (9347608) and a charity registered in England and Wales (1160558), Scotland (SC045584) and Isle of Man (1200). Registered Office: Fifth Floor, Ibex House, 42–47 Minories, London EC3N 1DY.
Leave a Reply