Methotrexate (children)

What is it?

Methotrexate (brand name: Methoblastin) is a medicine used to treat certain childhood rheumatic conditions (diseases which may affect joints, muscles, skin or eyes). These include juvenile arthritis (JIA), lupus (also known as SLE), uveitis, dermatomyositis and scleroderma.

Methotrexate is a medicine that works by suppressing the immune system. It reduces the damage done by inflammation, rather than just reducing pain. Because of this, it is called a disease modifying antirheumatic drug (DMARD). Other medicines in this group include leflunomide, sulfasalazine and hydroxychloroquine. Methotrexate is thought to work by affecting the immune system. It has been safely used for over 30 years. It is one of the most common medicines used by rheumatologists. It is also used at very high doses to treat some childhood cancers.

How will it help?

Methotrexate works slowly. You can expect your child to start feeling better, but it might take one to two months.

How is methotrexate given?

Methotrexate can be given as a tablet or an injection under the skin. When should it be given? It is taken once a week, on the same day every week. What is the dose? This depends on the size and weight of your child. It also depends on how extensive the disease is.

How long will it be used for?

Methotrexate can be continued long-term to maintain disease control.

Are there any side effects?

Methotrexate is usually very effective 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 methotrexate. Folic acid (a vitamin) is usually given to children on methotrexate to make these side effects less likely

Things you need to know about this medicine

What to do if your child is sick

It is safe to give methotrexate even if your child has a cold or cough. Don’t give methotrexate if your child:

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

If you’re not sure, talk to your doctor before giving the methotrexate. Interactions Methotrexate can interact with other medicines. Talk to your doctor before taking any prescription medicines, natural medicines and medicines that you can buy over the counter.

Immunisations

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

Infections

Methotrexate can make chickenpox infections more serious. A blood test can be done to see if your child is already immune to chickenpox. If your child is contact with chickenpox or shingles, their doctor should be called.

Alcohol

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

Sexual health

Being pregnant while on methotrexate, can be harmful for the baby. Patients who are sexually active, should use effective contraception to avoid getting pregnant. This should be continued for six months after methotrexate is finished. Having been on methotrexate in the past does not change a person’s fertility for the future nor does it change their chances of having babies later.

Myths and misconceptions

You may hear a lot of different information about methotrexate from friends, pharmacists or people you know. If you are worried about anything, please talk to your child’s doctor or nurse for more information. If your child is taking methotrexate 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.