What are the possible risks and side-effects of bisphosphonates?
Bisphosphonates are generally well tolerated. The risk of digestive problems with oral preparations is very much reduced if you carefully follow the instructions that come with your medicine.
Less common side-effects include:
- itchy rashes or photosensitivity (rash on exposure to sunlight)
- a sore mouth
- flu-like symptoms (more common with intravenous treatment)
- bone pain (more common with intravenous treatments)
- muscle pain
You should report any side-effects to your doctor or rheumatology nurse and the drug may be stopped if necessary.
There are three very rare side-effects:
- Osteonecrosis of the jaw is a condition where healing is incomplete following an invasive dental procedure. An area of bone is exposed through the gum and a small amount of bone dies. This condition is more common if you have cancer, are having chemotherapy or you have severe, recurrent dental infections and are having dental treatment.
- It's been suggested that there's a possible, though small, increase in the risk of cancer of the oesophagus (gullet) in people taking bisphosphonates by mouth for more than 3–5 years. However, the evidence is mixed and in most situations, the benefits of treatment are greater than any potential risk.
- Some people taking bisphosphonates have developed painful, partial or complete fractures in the upper, outer region of the thigh bone (femur) below the hip. Partial fractures are usually confirmed by a special diagnostic scan. The risk appears to increase the longer you've been taking these drugs, and may be greater if you're also having steroid treatment or have diabetes. However, it's still extremely rare.
Your doctor will review your treatment from time to time to make sure the benefits of the treatment still outweigh the risks. Most specialists limit treatment with oral bisphosphonates to five years (or three years for intravenous zoledronate) to minimise the risks of rare, long-term side-effects. However, some people will need more lengthy treatment.