Cyclophosphamide (children)

What is it?

Cyclophosphamide (brand name: Cycloblastin, Endoxan) is a medicine used to treat severe inflammatory diseases (diseases which may affect kidneys, blood vessels, joints, muscles, skin, gut or eyes). This can include complicated lupus (also known as SLE), vasculitis, uveitis and scleroderma. It is also used to treat certain cancers. Cyclophosphamide is a medicine that works by suppressing your immune system. It reduces the damage done by inflammation, rather than just reducing pain.

How will it help?

Cyclophosphamide is a medicine that works slowly. You can expect your child to gradually start feeling better, but it might take weeks to months.

How is Cyclophosphamide given?

Cyclophosphamide is given via a vein as an infusion, or as a tablet.

When should it be given?

Tablets: Daily

Infusion: Approximately once a month for the first six months.

What is the dose?

This depends on the weight of your child. When the disease is under control, other medicines may be started. The dose of cyclophosphamide may then be reduced.

How long will it be used for?

People may stay on cyclophosphamide for long periods (several years) to help keep their disease under control. The dose is usually reduced after the first six months.

Are there any side effects?

Cyclophosphamide is usually very effective in improving your child’s condition, but as with all medicines side effects can occur. Some are common, and some are rare. Most people don’t have any problems when they take cyclophosphamide. You must have regular blood tests while you are on cyclophosphamide.

Things you need to know when taking this medicine

What to do if your child is sick

Don’t give cyclophosphamide if your child:

  • Has a high fever
  • Has had vomiting/ diarrhoea
  • Has been in contact with chickenpox or shingles
  • Is sick and you’re not sure why

If you’re not sure, talk to your doctor, and get your child checked if necessary before giving the cyclophosphamide.


Cyclophosphamide can interact with many other medicines. Talk to your doctor before your child takes any prescription medicines, natural medicines and medicines that you can buy over the counter.


Most immunisations are safe to have (flu vaccine, cervical cancer vaccine, killed polio vaccine (IPV) etc). Live virus vaccines (such as mumps, measles, rubella (MMR), polio (OPV)), varicella (chicken pox) and some travel vaccines should not be used when taking cyclophosphamide.


Patients on cyclophosphamide are at increased risk of infection, because of immune suppression. Cyclophosphamide can make chickenpox infections more serious. A blood test can be done to see if somebody is already immune to the virus. If your child is in contact with chickenpox or shingles, call your doctor.


Cyclophosphamide and alcohol are both broken down by the liver. Drinking alcohol while taking cyclophosphamide can put extra strain on the liver. It is not known how much is safe, so it is suggested that anyone on cyclophosphamide should avoid drinking alcohol.

Sexual Health

Being pregnant while you are taking cyclophosphamide, it can be very bad for the baby. Patients who are sexually active, should use effective contraception to avoid getting pregnant. Women on cyclophosphamide may stop getting their periods but they usually return after the drug is stopped. Having been on cyclophosphamide may affect fertility for the future. Your doctor will discuss this before the medication is started.

Myths and misconceptions

You may hear a lot of different information about cyclophosphamide from friends, pharmacists or people you know. If you are worried about anything, please talk to your doctor or nurse for more information. If your child is taking cyclophosphamide they should see their paediatric rheumatologist regularly to make sure the treatment is working and to minimise any possible side effects.

This medicine should be kept in a safe place, as accidental overdose can be serious.

© Copyright Arthritis Australia March 2015. Reviewed December 2017. The Australian Paediatric Rheumatology Group contributed to the development of this information sheet.  This sheet is published by Arthritis Australia for information purposes only and should not be used in place of medical advice.