1. What is zoledronic acid?
Zoledronic acid is a drug 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.
Zoledronic acid is also prescribed:
- For people at risk of or who have osteoporosis
- As treatment for breast cancer that has spread to the bone
The following information is for women who are having it to reduce the risk of breast cancer spreading.
2. Who might be offered zoledronic acid?
Zoledronic acid 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 zoledronic acid if you are post-menopausal and have had treatment for invasive breast cancer that has spread to the 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 given?
Zoledronic acid is given as a drip into a vein in your arm. The medical name for this is an intravenous infusion.
The infusion takes at least 15 minutes.
It’s usually given every 6 months in the outpatient department of your hospital.
4. How long will I have zoledronic acid for?
You will usually be advised to have zoledronic acid for 3 to 5 years.
5. Side effects of zoledronic acid
Like any drug zoledronic acid 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 zoledronic acid, you may also have 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.
Diarrhoea
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.
Flu-like symptoms
Zoledronic acid can cause flu-like symptoms such as joint and muscle pain, fatigue, shivering and fever. These can last for a few days.
Your treatment team can advise you about taking mild pain relief to help.
Red or sore eyes
Your eyes may be sore or red for a few days after your treatment. Your treatment team can prescribe eyedrops to relieve this.
Anaemia
Having too few red blood cells is called anaemia. If you feel particularly tired, breathless or dizzy let your treatment team know.
Less common side effects
Low calcium levels in the blood
Zoledronic acid can cause calcium levels in the blood to drop too low. This is called . You’ll have regular blood tests to check the 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.
Allergic reaction
Zoledronic acid can cause an allergic reaction. If you become breathless or start to develop an itchy rash let your treatment team know straight away.
Bone, joint or muscle pain
Some people have bone, joint or muscle pain for a short time after having zoledronic acid. Let your treatment team know if you experience any of these symptoms.
Headaches
Let your treatment team know if you get headaches. They can advise you about what medicines to take.
Osteonecrosis
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 an uncommon but serious side effect of zoledronic acid.
Symptoms include:
- Lasting jaw pain
- Loose teeth
- Swelling, redness or ulcers on the gums
Let your treatment team and dentist know straight way 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 zoledronic acid. Let them know you’ll be starting treatment and speak to your treatment team if your dentist recommends any dental treatment before starting or while having zoledronic acid.
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.
Fracture
Although it’s rare, zoledronic acid 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 having zoledronic acid for a long time.
If you have lasting pain in your thigh, hip or groin, let your treatment team know.
Effects on the kidneys
Zoledronic acid can affect the way the kidneys work. You should have blood tests to monitor this.
