Bisphosphonate therapy

Bisphosphonates are a group of drugs used to manage and prevent complications from cancer in the bone. This information leaflet explains how they work, when they may be prescribed and what side effects may occur.

How do bisphosphonates work?

Healthy bones are constantly being broken down and renewed. This process is a delicate balance of the breaking down of old bone and the rebuilding of new bone. When cancer spreads to the bone, the process is disrupted and usually more bone is broken down than is replaced. This can cause pain and weakening of the bones, which means they may be more at risk of fracture.
Bisphosphonates work by slowing down the process of bone breakdown.

When are bisphosphonates prescribed?

Bisphosphonates are used to help control bone pain and reduce the risk of possible problems, such as fractures. They are given regularly and may be given indefinitely or until your Specialist assesses that you will no longer benefit from them.
Bisphosphonates are also used to treat a condition called hypercalcaemia (high calcium levels), which can be a complication of cancer. This is where too much calcium leaks from the bones into the bloodstream and causes symptoms such as excessive thirst, nausea, fatigue, weakness, poor appetite and constipation,
confusion and drowsiness.

How are bisphosphonates given?

Bisphosphonates are most commonly given through a drip (intravenously), although in some cases they can be given by mouth. At the Hospice we offer an out-patient clinic which you can attend regularly for your treatment.

What are the commonly used bisphosphonates?

A number of different bisphosphonates are used in the management of secondary bone cancer. The two most commonly used by the Hospice are pamidronate and zoledronic acid.
Disodium pamidronate is given intravenously over approximately 1½-2 hours, every 3-4 weeks.
Zoledronic acid is given intravenously over a period of at least 15 minutes, every 3-4 weeks.

What are the side effects of bisphosphonates?

Bisphosphonates can cause a variety of side effects. The more common side effects usually occur within the first 48 hours after treatment and get better on their own; these are headache, bone or muscle pain, or joint discomfort. You may experience flu-like symptoms such as fever, hot flushes and chills after the first treatment.

Less common side effects may include pain and/or redness or inflammation at the injection site. You may also experience generalised pain, tiredness, nausea and vomiting. Most patients find these side effects are manageable and time limited. Rare side effects include muscle cramps, abdominal pain, agitation, dizziness, sleeplessness, drowsiness and  exhaustion.