Zoledronic acid

Bone cells constantly renew themselves. This helps bones keep their strength and shape.

There are 2 types of cell inside the bones. These are called: 

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

As we get older, osteoclasts begin to break down more bone than osteoblasts make to replace it. This means our bones slowly become thinner (less dense). In some people, too much of the bone density is lost and this increases the risk of osteoporosis and bone fractures. 

Some secondary bone cancers make a substance that causes osteoclasts to destroy more bone than can be replaced. The affected bone becomes weak and painful and can break more easily.

Bones contain calcium, which gives them strength. A bone affected by cancer may cause calcium from the bones to be released into the blood. A raised level of calcium in the blood is called hypercalcaemia. This may cause symptoms including:

• feeling sick (nausea)
• being sick (vomiting)
• feeling thirsty
• needing to pee (pass urine) more often 
• constipation
• tiredness
• irritability
• confusion.

When you have your treatment, you will meet someone from your cancer team, such as a:

• cancer doctor
• specialist nurse
• specialist pharmacist.

This is who we mean when we mention doctor, nurse or pharmacist in this information.

During the course of your treatment, you will have regular blood tests. This is to check that it is safe for you to have treatment.

You will meet with a doctor, nurse or pharmacist before you have treatment. They will talk to you about your blood results and ask how you have been feeling.

Zoledronic acid can be given on its own or with other cancer treatments.

You have zoledronic acid by a drip (infusion) into the vein. You usually have it in the outpatient department at the hospital. The infusion takes at least 15 minutes. It is usually given once every 3 to 4 weeks.

You may have it through 1 of the following:

• a cannula – a short, thin tube the nurse puts into a vein in your arm or hand
• a central line – a fine tube that goes under the skin of your chest and into a vein close by
• a PICC line – a fine tube that is put into a vein in your arm and goes up into a vein in your chest
• an implantable port (portacath) – a disc that is put under the skin on your chest or arm and goes into a vein in your chest.

How long zoledronic acid is given for depends on why you are having the treatment.

• If you are having zoledronic acid to help prevent cancer coming back, you will have an infusion once every 6 months for 3 to 5 years.
• If you are having zoledronic acid to reduce pain or strengthen your bones, you usually have an infusion every 3 to 4 weeks. You may also need to take calcium and vitamin D supplements. You usually need to take zoledronic acid for at least 2 to 3 months for it to have the full effect on your bones. After that, you can usually take it for as long as it is working well.
• If you are having zoledronic acid to lower calcium levels in your blood, it is usually given as a single dose. 

Your doctor will tell you more about your treatment and how long you may need to have it.  

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

You may get some of the side effects we mention, but you are unlikely to get all of them. And you may have some side effects, including rarer ones, that we have not listed here. 

Other cancer treatments may cause different side effects. If you are also having other cancer treatment, you may have other side effects.

Always tell your doctor, nurse or pharmacist about any side effects you have. They can give you: 

• drugs to help control some side effects 
• advice about managing side effects. 

It is important to take any drugs exactly as explained. This means they will be more likely to work for you.

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.

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.

Some people have flu-like symptoms, such as:

• a high temperature
• chills
• fatigue (tiredness)
• pains in your muscles or joints. 

Tell your doctor if these symptoms do not get better within 2 days or are getting worse. It may help to take mild painkillers, such as paracetamol. Contact the hospital on the number you have been given. Your doctor, nurse or pharmacist can give you advice. 

Feeling tired is a common side effect. Try to pace yourself and plan your day so you have time to rest between activities.

Being physically active can help to manage tiredness and give you more energy. It also:

• helps you sleep better
• reduces stress
• improves your bone health.

If you feel sleepy, do not drive or operate machinery.

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

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

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

This treatment can reduce the number of red blood cells in your blood. Red blood cells carry oxygen around the body. If the number of red blood cells is low, this is called anaemia. You may feel:

• very low in energy
• breathless 
• dizzy and light-headed. 

If you have these symptoms, contact the hospital straight away on the 24-hour number. You may need treatment for anaemia. If you are very anaemic, you may need a drip to give you extra red blood cells. This is called a blood transfusion.

You may have headaches or feel dizzy at times when taking this treatment. Tell your doctor if you notice these symptoms.

This treatment can cause eye problems. If you have any of these symptoms during treatment or after it finishes, contact the hospital on the 24-hour number straight away. Contact them if:

• you notice any change in your vision, such as double vision or things appear blurry or faded 
• your eyes get red and inflamed (conjunctivitis)
• you have pain in your eyes
• your eyes are sensitive to light

You may need to have an eye check with a specialist eye doctor (ophthalmologist).

You may feel sick or be sick (vomit) while having this treatment. This is usually mild. Your doctor can prescribe anti-sickness drugs to help prevent or control sickness. 

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

This treatment can affect your appetite. Don’t worry if you do not eat much for 1 or 2 days. But if your appetite does not come back after a few days, or if you are losing weight, tell your doctor, nurse or pharmacist. They can give you advice. They may give you food or drink supplements. Or they may suggest changes to your diet or eating habits to help.

This treatment can affect how the kidneys work. This is usually mild and goes back to normal after treatment ends. You will have blood tests to check how well your kidneys are working. Contact the hospital on the 24-hour number if you:

• have blood in your urine (pee) 
• are passing less urine or peeing less often than usual.

Drinking fluids helps protect your kidneys. The advice is usually to try to drink at least 2 litres (3½ pints) of fluid each day. But follow any advice from your doctor, nurse or pharmacist about how much is right for you.

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

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. They will tell you if you need any supplements. This will depend on blood test results.

This treatment can affect how the heart works. You may have tests to check how well your heart is working. These may be done before, during and after treatment.

If the treatment is causing heart problems, your doctor may change the type of treatment you are having.

Contact the hospital straight away on the 24-hour number if you have any of these symptoms during or after treatment:

• breathlessness
• dizziness
• changes to your heartbeat (palpitations)
• swollen feet and ankles.

Other conditions can cause these symptoms, but it is important to get them checked by a doctor.

Always call 999 if you have:

• chest pain, pressure, heaviness, tightness or squeezing across the chest
• difficulty breathing.

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.

Some foods may taste different or have no taste. Try different foods to find out what tastes best to you. You may also get a bitter or metallic taste in your mouth. Your doctor, nurse or pharmacist can give you advice. It might help to try:

• sucking sugar-free sour or boiled sweets
• eating cold foods
• eating sharp-tasting fresh fruit.

Taste changes usually get better after treatment ends. We have more information about coping with changes to taste.

You may get pain in your tummy (abdomen), or have indigestion. Your doctor, nurse or pharmacist can give you advice or treatment to help. Contact the hospital straight away on the 24-hour number if your symptoms do not go away, or get worse.

Chemotherapy can affect your skin. It might feel dry. You may develop a rash, which may be itchy. Always tell your doctor, nurse or pharmacist about any skin changes. They can give you advice or prescribe creams or medicines to help.

If your skin feels dry, try using soap-free cleansers and unperfumed moisturising cream every day.

This treatment can cause changes to the lungs. Tell your doctor, nurse or pharmacist if you develop: 

• a cough that does not go away
• wheezing
• breathlessness.

You should also tell them if any existing breathing problems get worse. You may have tests to check your lungs.

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
• if you smoke
• if you have gum disease
• if you wear 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. Your healthcare team can tell you more.

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

• have a full dental check-up before starting treatment 
• have good oral hygiene by looking after your teeth and gums during treatment – ask your dentist for advice
• have regular dental check-ups
• tell your dentist you are taking a bisphosphonate before having any dental treatment.

Tell your doctor and dentist straight away if you develop:

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

Very rarely, the small 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.