Cyclophosphamide

Cyclophosphamide is used to treat a variety of different cancers, and severe inflammatory conditions such as systemic lupus erythematosus (SLE/lupus). Find out how to take it safely and the possible side effects.

What is cyclophosphamide?

Cyclophosphamide is an immunosuppressive medicine which means it interrupts the activity of your immune system, slowing the disease and reducing inflammation. It is used to treat some cancers and severe inflammatory illnesses such as complicated systemic lupus erythematosus (SLE/lupus).

Dose

In Aotearoa New Zealand cyclophosphamide is available as an injection and tablets (50 mg). The information on this page is mainly about cyclophosphamide tablets.

  • The dose of cyclophosphamide is different for different people. Your doctor will calculate your dose based on your condition, blood test results and response to treatment.
  • Always take your cyclophosphamide exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much to take, how often to take it and any special instructions.

How to take cyclophosphamide tablets?

  • Timing: Cyclophosphamide is best taken with food. Take your dose early in the day. If you are taking 1 dose daily, take it at breakfast. 
  • Swallow your tablets whole with a full glass of water: Do not crush or chew them.
  • Avoid or limit alcohol: Avoid heavy or binge drinking because it can increase your risk of side effects, such as problems with your liver. 
  • Missed dose: If you forget to take your dose, take it as soon as you remember. But, if it is nearly time for your next dose, take the next dose at the right time. Do not take extra doses to make up for a forgotten dose. If you are not sure what to do, ask your healthcare provider.
  • Keep taking cyclophosphamide regularly: Cyclophosphamide does not work straight away. It usually takes a few weeks before you notice the full benefits. If you stop cyclophosphamide treatment for more than a few weeks there is a risk that your condition may worsen.

What to consider when taking cyclophosphamide

Drink plenty of liquids

Cyclophosphamide can irritate the lining of the bladder so it is important to drink plenty of fluid to ‘flush out the bladder’. Eight to 10 glasses of water a day is recommended. 

Depending on your dose you may be told to empty your bladder (pass urine) frequently, every 2 hours while you are awake, and at bedtime for at least 24 hours after your dose. Your doctor may also tell you to get up in the night to empty your bladder. This helps prevent bladder and kidney problems.

Taking other medicines and supplements

Cyclophosphamide can interact with some medicines, herbal supplements and rongoā Māori, so check with your doctor or pharmacist before starting cyclophosphamide and before starting any new products.

You may need regular blood tests

While you are taking cyclophosphamide you will need to have regular blood tests to check the treatment is working and to monitor for side effects. 

Get the flu vaccine every year

Keep your flu vaccination up to date to reduce your risk of getting the flu. It is safe for you to have the annual flu vaccine. Some vaccines should not be taken if you are taking cyclophosphamide. Always check with your doctor or pharmacist first.

Pregnant or planning a pregnancy

Cyclophosphamide should not be taken if you are pregnant. If either you or your partner are taking cyclophosphamide, talk to your doctor about contraception. If you or your partner wish to become pregnant, ask your doctor about stopping cyclophosphamide. It should not be taken for at least 3 months before pregnancy.

Tell your healthcare providers

Make sure you tell anyone providing you with health, dental or medical care that you are taking cyclophosphamide.

Possible side effects of cyclophosphamide

Like all medicines, cyclophosphamide can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.

Side effects What should I do?
  • Feeling sick (nausea) 
  • Vomiting (being sick)
  • Diarrhoea (runny poo)
  • Take your dose with food.
  • Tell your doctor if they bother you.

  • Tiredness
  • Headache
  • Muscle and joint pains
  • These are quite common when you first start taking cyclophosphamide and usually go away with time.
  • Tell your doctor if they bother you.
  • Signs of problems with your lungs such as dry cough, shortness of breath, difficulty breathing or chest pain.
  • Lung problems ate rare but serious. 
  • Tell your doctor immediately or phone Healthline on 0800 611 116.
  • Signs of changes in your blood cells, such as a sore mouth, sore throat, mouth ulcers, easy bruising, nosebleeds, bleeding gums, shortness of breath, fever or infection
  • Changes in your blood cells are rare but serious.
  • Tell your doctor immediately or phone Healthline on 0800 611 116.
  • Signs of problems with your liver, such as sudden pains in your stomach, loss of appetite or yellowing of your skin and eyes
  • Liver problems are rare but serious.  
  • Tell your doctor immediately or phone Healthline on 0800 611 116.

Learn more

The following links have more information on cyclophosphamide. Be aware that websites from other countries may contain information that differs from New Zealand recommendations:

NZ Formulary Patient Information

Australian Rheumatology Association Cyclophosphamide 

References

  1. Cyclophosphamide New Zealand Formulary
Credits: Health Navigator Pharmacists. Reviewed By: Maya Patel, MPharm PGDipClinPharm, Auckland Last reviewed: 09 May 2022