Pamidronate (Aredia®)

Pamidronate Back to top

Pamidronate belongs to a group of drugs called bisphosphonates|. Bisphosphonates are commonly used to treat bone thinning (osteoporosis). In certain situations, they can help protect your bones against some of the effects of secondary bone cancer|, such as pain and weakness. Secondary bone cancer occurs when the original (primary) cancer spreads to form a secondary cancer (metastasis) in the bone.

Pamidronate is often given alongside other cancer treatments. As well as being used
in some types of secondary bone cancer, it has been shown to be effective in people with myeloma|, a cancer of the plasma cells in the blood. It is also used to lower a raised calcium level in the blood.

The effect of cancer on the bones Back to top

In secondary bone cancer, calcium, which helps strengthen the bones, can be lost from the damaged bone and seep into the bloodstream. A raised level of calcium in the blood is known as hypercalcaemia|. This can cause symptoms such as feeling or being sick (nausea or vomiting), tiredness, irritability and sometimes confusion. Pamidronate can help reduce high levels of calcium.

Secondary cancer in the bones may make them weak|, and in some situations they may fracture or break. Pamidronate can help to re-strengthen the bone and reduce the risk of fractures.

Cancer can affect the bones in different ways, and pamidronate is not helpful for all cancers that affect the bones. Your doctor or specialist nurse can tell you if it would be helpful for you.

How pamidronate works Back to top

In normal bone, two types of cell called osteoclasts and osteoblasts work together constantly to shape, rebuild and strengthen existing bone:

• osteoclasts destroy old bone
• osteoblasts build new bone.

Myeloma and some secondary bone cancers can produce chemicals that make the osteoclasts work harder. This means that more bone is destroyed than rebuilt, which leads to weakening of the affected bone. This can cause pain and means that the bone can fracture or break more easily.

Pamidronate targets areas of bone where the osteoclast activity is high. It helps bring the balance of osteoclast and osteoblast activity back to normal by reducing the activity of the osteoclasts. This can reduce pain and help strengthen the bone. It also means that less calcium will be lost from the bones.

How it is given Back to top

Pamidronate is given by a drip (infusion) into the vein through a fine tube called a cannula. It can usually be given in the outpatient department at the hospital. The infusion is given over several hours every 3–4 weeks.

How long it is given for Back to top

If you are having pamidronate to reduce pain or strengthen your bones, you may need to take it for as long as it seems to be working.

Pamidronate to lower calcium levels is usually given in a single 'one-off' dose. It can also be given over 2–4 days as multiple infusions.

Possible side effects Back to top

Some people have very few side effects while others may experience more. The side effects described below won't affect everyone who is having pamidronate and may be different if you are having more than one drug.

We have outlined the most common side effects but haven't included those that are rare and therefore unlikely to affect you. If you notice any effects that aren't listed below, discuss them with your doctor or nurse.

Increased pain

Sometimes pain| in the affected bone can temporarily become worse when you first take pamidronate. If this happens, your doctor can prescribe pain-relieving drugs until this side effect wears off.

Sometimes in the affected bone can temporarily become worse when you first take pamidronate. If this happens, your doctor can prescribe pain-relieving drugs until this side effect wears off.

Flu-like symptoms

These include a high temperature, chills and pains in your muscles or joints. Let your doctor know if these effects are troublesome. It may be helpful to take mild painkillers.

Less common side effects Back to top

Drop in calcium levels below normal

This is rare and usually only temporary. Your doctor will carry out regular blood tests to monitor the level of calcium in your blood.

Feeling sick (nausea) or being sick (vomiting)

This can be prevented with anti-sickness (anti-emetic)| medication. Tell your doctor if the sickness is not controlled.

Abdominal (tummy) pain, constipation or diarrhoea

Abdominal (tummy) pain, constipation| or diarrhoea| can usually be controlled with medicine, but let your doctor know if it is severe or continues.

Pain or redness at the injection site or painful veins

Let your doctor or nurse know if you have these problems.

Red or sore eyes

Your doctor can prescribe eye drops to ease this.

Change in kidney function

Sometimes pamidronate can affect how the kidneys work. This does not usually cause any symptoms and the effects are generally mild. Your doctor will monitor how well your kidneys are working during your treatment by doing regular blood tests.

Headaches

This is not common. It is important to drink plenty of fluids. Let your doctor know if you are getting headaches, as they can prescribe medication.

Jaw problems (osteonecrosis)

An uncommon side effect of pamidronate is a condition called osteonecrosis of the jaw. This is when healthy bone tissue in the jaw becomes damaged and dies. Gum disease, problems with your dentures and some dental treatments, such as having a tooth removed, can increase the risk of this. So before you start taking the drug you'll be advised to have a full dental check-up.

During treatment with bisphosphonates, it's very important to look after your teeth by brushing them regularly and having routine dental check-ups. Always let your dentist know that you're taking bisphosphonates.

Some of the symptoms of osteonecrosis can include pain, swelling, redness of the gums, loose teeth or a feeling of numbness or heaviness in your jaw. Tell your cancer specialist and dentist straight away if you have any of these symptoms.

References Back to top

This section has been compiled using information from a number of reliable sources, including:

• Aston V. Managing bone metastases through bisphosphonate treatment. Cancer Nursing Practice. 2005. Vol 4.
• Migliorati CA, et al. Bisphosphonate-Associated Osteonecrosis: a Long-Term Complication of Bisphosphonate Treatment. Lancet Oncology. 2006. Vol 7: 508–514.
• Parker CC. The role of bisphosphonates in the treatment of prostate cancer. BJN International. 2005. 95: 935–938.
• British National Formulary. 59th edition. 2010. British Medical Association and Royal Pharmaceutical Society of Great Britain.
• Reid D, et al. Guidance on the management of breast cancer treatment-induced bone loss: A consensus position statement from a UK expert group: Cancer Treatment Reviews. 2008. 34: S3–S18.