What is this medication for?

• Methotrexate is a medicine that reduces over-activity of the immune system. It is used to treat various autoimmune diseases including rheumatoid arthritis, systemic lupus erythematosus (SLE), juvenile idiopathic arthritis, psoriasis, psoriatic arthritis, uveitis, and inflammatory myositis (muscle inflammation).

• In arthritis, methotrexate acts as a disease modifying anti-rheumatic drug (DMARD) that helps to reduce pain, swelling, and long-term joint damage.

How should I take/use this medication?

• A typical weekly dose of methotrexate ranges from 7.5mg to 25mg, given in the form of tablets or injection. Dosage may vary depending on your disease activity and response to the medicine.

• Tablets should be taken with or after food. It should be swallowed whole with a glass of water, without chewing or crushing. Wash hands thoroughly after administration.

• Folic or folinic acid (also called folate) is often given to reduce the risk of some side effects. It is usually taken a day before or after methotrexate unless advised otherwise by your doctor.

• The beneficial effects of methotrexate will begin after 6 weeks and the full benefits may not be seen until after 12 weeks of treatment. Thus, it is important that you take your medication regularly, otherwise you may not benefit at all.

• Medications, such as corticosteroids, non-steroidal anti-inflammatory drugs (NSAIDs) and other DMARDs may be taken with methotrexate.

What should I do if I forget to take/use this medication?

• If you miss a dose, take it as soon as you remember if it is within 2 days from your scheduled dose. For example, if your scheduled dose is on Sunday and you remember your forgotten dose on Tuesday, take the dose on Tuesday and resume the Sunday schedule in the same week. Skip the dose if 3 or more days have lapsed since the missed dose. Do not take double doses to make up for the missed dose.

What precautions should I take?

Inform your healthcare professional if:

• You are allergic to this medication or any of the other ingredients of this medication

• You are taking any other medications, including over-the-counter medicines, supplements, traditional medications and herbal remedies.

• Inform your doctor if you have any liver disease (e.g. jaundice, hepatitis) or if any of your family members has hepatitis.

Conception and breastfeeding precautions:

• For female patients, please inform your doctor if you intend to conceive or breastfeed. This is because methotrexate can cause miscarriage and serious birth defects, and should be avoided before conceiving and during pregnancy. Reliable contraceptive measures must be used to avoid unplanned pregnancy whilst taking methotrexate. Patients should also wait at least three months after stopping methotrexate before trying for a child. In addition, women are advised not to breastfeed as methotrexate is excreted into the breast milk.

• For male patients who are considering to have children, the continued use of methotrexate may be considered. Please discuss with your primary rheumatologist.

What are some common side-effects of this medication?

• Mouth ulcers

  • Folic or folinic acid can be prescribed to reduce this side effect

• Nausea, vomiting, diarrhoea or loss of appetite

  • If affected, take medication after food to minimise the side effects. Folic/folinic acid can be prescribed to reduce this side effect. Alternatively, methotrexate can be converted to an injection form. Consult your doctor immediately if you see bloody vomit or stools.

• Slow loss of hair

  • Generally reversible when the medicine is discontinued.

• Skin rashes

  • Usually resolve readily upon decreasing the dose or stopping the medicine.

Consult your doctor immediately if you experience any of the following side effects:

• Lung inflammation (Warning signs: Persistent coughing, breathlessness or chest pain)

  • If you are currently smoking, it is advisable to stop smoking.

• Liver disorder (Warning signs: Yellowing of eye whites or skin, dark or tea-coloured urine, or constant abdominal pain)

• Blood disorders (Warning signs: May be asymptomatic; unusual bleeding or bruising, lip or mouth ulcers with “flu-like” symptoms may occur)

  • Monitoring the effects of your new treatment is important for early detection of side effects. For your safety, you need to do regular blood tests for monitoring.

• Infections e.g. shingles, chickenpox (Warning signs: Fever, chills, persistent severe sore throat or mouth ulcers)

What are some rare but serious side-effects that I need to seek medical advice immediately?

The symptoms of a drug allergy include one or more of the following:

• Swollen face/eyes/lips/tongue

• Difficulty in breathing

• Itchy skin rashes over your whole body

If you experience any of these symptoms, you should stop your medication and see your healthcare professional immediately.

What food or medication should I avoid when I take this medication?

• Avoid crowded places and consumption of raw or undercooked food while on methotrexate

• Pneumococcal and influenza (flu) vaccinations are safe and may be given if required. Avoid live vaccines such as MMR (measles, mumps and rubella), OPV (oral polio vaccine), yellow fever or BCG (tuberculosis). Discuss with your doctor before receiving any vaccines. Also, direct contact with persons who have taken oral polio vaccine or those with infections should be avoided.

• Do not drink alcohol while on this medicine as it may increase the risk of liver toxicity associated with methotrexate.

How should I store this medication?

Store in a cool and dry place, away from direct sunlight. Keep this medication away from children.

How should I throw away this medication safely?

Empty blisters may be packed and sealed in a plastic bag before throwing it into the rubbish chute or bin. For unused medications, return to the pharmacy for proper disposal.

Disclaimers

If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (National Healthcare Group, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.

Last updated on Jun 2022