Why am I being prescribed cyclophosphamide?
Cyclophosphamide is used for several different types of rheumatic disease, including systemic lupus erythematosus (SLE), vasculitis and sometimes for rheumatoid arthritis. It is a very powerful drug and may have effects on the immune system (the body’s own defence system). One of its actions is to reduce the activity of the immune system, and it is only prescribed under very close supervision. Cyclophosphamide is often prescribed along with steroid tablets.
When do I take cyclophosphamide, and what dose will I be prescribed?
There are several different ways in which cyclophosphamide can be prescribed. Your doctor will decide which is best for you and discuss this with you. The dose will depend on your body weight and may change depending on how you respond to the cyclophosphamide. The 3 main ways are as follows:
- Low doses of tablets, usually taken once a day.
- High doses of tablets taken less often, for example, once every 2 weeks.
Tablets should be taken with or after food, preferably in the morning or early afternoon.
They should be taken with plenty of water and swallowed whole, not chewed. - By injection into a vein (intravenous injection). Your doctor will decide how frequently you should have these injections. The injections need to be given in hospital.
How long will cyclophosphamide take to work?
Cyclophosphamide does not work immediately. It may take 6 weeks or more to produce an effect, depending on the illness for which it is being given.
What are the possible side-effects?
A common side-effect is nausea. Your doctor may prescribe medicine to reduce the nausea.
One very important side-effect of cyclophosphamide is inflammation and bleeding of the bladder wall (haemorrhagic cystitis). If this occurs you may notice blood in your urine and you must report to your doctor immediately. To reduce the risk of this happening, you should increase the number of non-alcoholic drinks each day to the equivalent of 8 to 10 glasses of water. Some doctors prescribe a drug called MESNA along with cyclophosphamide to try and reduce the risk of cystitis.
Cyclophosphamide can also reduce the blood count. Taking cyclophosphamide can make you more likely to develop infections. If you have fever, infections, unexplained bruising or bleeding you must tell your doctor immediately.
Other possible side-effects are loss of hair, mouth ulcers, and irregular menstrual periods. If you develop these or any other new symptoms after starting cyclophosphamide, you should tell your doctor.
If you develop chicken-pox or shingles, you should go to your doctor immediately as you may need special treatment.
Do I need any special tests while on cyclophosphamide?
Because cyclophosphamide can affect the blood and the bladder, your doctor will arrange for you to have regular blood and urine tests while on cyclophosphamide. You may be asked to keep a record booklet with your blood and urine test results. Bring this with you when you visit your doctor. It is important to have regular blood tests while on cyclophosphamide.
Can I take other medicines along with cyclophosphamide?
Some drugs interact with cyclophosphamide and you should always tell any doctor treating you that you are taking cyclophosphamide. You should not take ‘over-the-counter’ preparations without discussing this first with your doctor. However, many drugs can be safely taken with cyclophosphamide.
Can I have immunisation while on cyclophosphamide?
You should avoid immunisation which involve any of the live vaccines such as BCG, measles, mumps, polio and rubella (German Measles).
Does cyclophosphamide affect fertility or pregnancy?
Cyclophosphamide can reduce fertility in both men and women. Therefore, for young patients, it is used with caution. The effect may be reversible if you stop taking cyclophosphamide.
Cyclophosphamide should not be used by pregnant women. All patients should take appropriate contraceptive precautions while on cyclophosphamide and also for 6 months after treatment is stopped. If you are planning a family or if you become pregnant while taking cyclophosphamide, you should discuss this with your doctor as soon as possible. You should not breast feed if you are taking cyclophosphamide.