New measures to avoid potentially fatal dosing errors with methotrexate

Methotrexate is authorised for two different groups of indications, each with a different administration schedule:

• treatment of certain types of cancer of the breast, skin, head and neck, or lung for which the dosing frequency depends on the regimen and can involve daily administration of methotrexate;
• treatment of inflammatory diseases including rheumatoid arthritis, psoriasis and Crohn’s disease, which require once-weekly use of a low dose of methotrexate.

Methotrexate can be taken orally or given by injection.

Methotrexate is usually not taken every day. You must use the correct dose for your condition. Some people have died after taking methotrexate every day by accident.

European medicine agency has recommended new measures to prevent serious and potentially fatal errors with the dosing of methotrexate for treating inflammatory diseases such as rheumatoid arthritis, psoriasis and Crohn’s disease. The recommendations result from a review of reports that patients are using methotrexate incorrectly despite previous measures to prevent errors.

For inflammatory conditions, methotrexate must be used just once a week. Using methotrexate more frequently than intended can result in serious side effects. The review found that the error in dosing frequency can occur at any step from prescribing the medicine to the patient taking it.

The new measures to prevent errors include restricting who can prescribe these medicines, making warnings on the packaging more prominent and providing educational materials for patients and healthcare professionals. In addition, to help patients follow the once-weekly dosing, methotrexate tablets will be provided in blister packs and not in bottles (or tubes). The measures were agreed after consultation with patients and healthcare professionals.

Information for patients

• If you are taking methotrexate for rheumatoid arthritis, psoriasis or Crohn’s disease, you must take it just once a week.
• Take your methotrexate medicine on the same day every week.
• Follow the instructions on the packaging of your methotrexate medicine.
• You will receive a patient card with your methotrexate tablets (or oral liquid). Read it carefully because it tells you how to take your medicine.
• Show your patient card to any new healthcare professional who treats you so that they know that you take your methotrexate medicine once a week.
• Methotrexate can cause serious or life-threatening side effects. Tell your doctor if you have diarrhoea, mouth sores, cough, shortness of breath, upper stomach pain, dark urine, numbness or tingling, muscle weakness, confusion, seizure, or skin rash that spreads and causes blistering and peeling, unusual bruising or bleeding, or signs of infection (fever, chills, body aches). These can be signs of taking too much methotrexate.
• Always attend your scheduled clinic visits and blood test appointments. They are important for making sure that your methotrexate medicine is working and that it is not causing any concern.
• If you are not sure about how to take your methotrexate medicine or you have any questions about it, talk to your doctor or pharmacist.

Information for healthcare professionals

Healthcare professionals should follow these recommendations:

• Methotrexate for inflammatory conditions is intended for use just once a week. Serious side effects including fatalities have occurred when methotrexate is taken more often.
• Only physicians with expertise in using methotrexate medicines should prescribe them.
• Healthcare professionals who prescribe or dispense methotrexate for inflammatory conditions should:
  • read the educational materials for oral methotrexate medicines;
  • ensure that they are familiar with the latest changes to the summaries of product characteristics for methotrexate medicines used for inflammatory conditions;
  • give clear instructions to the patient (or carer) about once-weekly dosing;
  • check carefully that the patient (or carer) understands that the medicine must be used once a week, and do this each time a new prescription is issued or the medicine is dispensed;
  • decide together with the patient (or carer) on which day of the week the patient uses methotrexate;
  • counsel the patient (or carer) about signs of methotrexate overdose and give instructions to promptly seek medical advice in case of suspected overdose.