Why Do You Need Liver Blood Tests on Methotrexate, and What If ALT Is Raised?

Methotrexate can, in some people, affect the liver, so clinicians check liver blood tests together with a full blood count and kidney function before and during treatment. The aim is to catch changes early, often before any symptoms appear. Regular testing is a normal part of taking methotrexate and does not mean something is wrong.

This guide is for adults taking methotrexate for conditions such as rheumatoid arthritis, psoriasis or Crohn's disease. It explains routine monitoring and what a raised ALT can mean. It cannot interpret your own result or tell you whether to keep taking the medicine.

NHS guidance says to contact a doctor or urgent advice line immediately for any of the following while taking methotrexate. Do not wait for your next routine blood test. Call your local emergency number for signs of a serious allergic reaction, such as sudden swelling of the lips, mouth, throat or tongue, difficulty breathing or fainting.

• Yellowing of the skin or the whites of the eyes, which can be harder to see on brown or black skin.
• Fever, feeling hot, cold or shivery, muscle aches or a sore throat, which may be signs of infection.
• Bleeding gums, blood in the urine, vomiting blood or bruising with no clear cause.
• A lasting cough, chest pain or new breathlessness.
• Swollen hands, ankles or feet, or a change in how often you pass urine, or passing none.
• Possible liver problems listed by MedlinePlus: persistent nausea, unusual tiredness, poor appetite, weight loss, upper right abdominal pain, itching or flu-like symptoms.

NHS patient guidance says that after starting, people usually have check-ups and blood tests every 1 to 2 weeks to check the blood, liver and kidneys. Once the dose is settled and treatment is working, this usually drops to every 2 to 3 months. Doses and results are usually recorded in a booklet, which is worth bringing to appointments.

Schedules differ by specialty and country, and they usually become more frequent again after a dose change. UK pharmacy monitoring guidance for clinicians lists liver function tests, a full blood count and kidney function before starting, and also checks for hepatitis B, hepatitis C and HIV. Your team will tell you which tests you need and when.

ALT (alanine aminotransferase) is an enzyme that can rise when liver cells are irritated or injured. MedlinePlus explains that a high ALT does not always mean there is a condition that needs treatment, and that the level does not show how much damage there is. Compare your number with the reference range on your report, because laboratories set their own ranges.

Clinicians look at the size of the rise and the trend over several tests. Clinician guidance from the NHS Specialist Pharmacy Service highlights that steadily rising liver enzymes, or a gradual fall in albumin, can matter even when single results are within range. Depending on the picture, the team may repeat the test, review other medicines and alcohol, adjust the dose or pause treatment and seek specialist advice. That is a decision for the prescriber.

A raised ALT is not always caused by methotrexate. MedlinePlus lists other medicines such as some cholesterol and pain medicines, dietary supplements, intense exercise and factors such as weight. Alcohol and other liver conditions are also considered. Our guides on raised ALT with a normal ultrasound and on elevated GGT explain these other causes in more detail.

Some medicines interact with methotrexate. NHS guidance asks people to tell their doctor about anti-inflammatory painkillers such as ibuprofen, some antibiotics including trimethoprim and co-trimoxazole, certain diuretics, epilepsy medicines and indigestion medicines such as omeprazole. Bring a full list, including herbal remedies and supplements.

Advice on alcohol differs between sources and depends on your dose and health. The American College of Rheumatology says alcohol can significantly increase the risk of liver damage and advises avoiding it, while MedlinePlus advises asking your doctor how much alcohol, if any, is safe. Tell your team honestly how much you drink, including in the past, and ask what applies to you.

Folic acid is often prescribed alongside methotrexate to reduce some side effects. Take it only as your prescriber directs. NHS guidance says not to take extra vitamin or mineral supplements containing folic acid or folate as well, unless your doctor agrees.

Do not stop, skip or change methotrexate without talking to the prescriber. NHS guidance notes that methotrexate is often taken for several years to keep symptoms controlled, and the team may prefer a different response, such as repeating the test or adjusting the dose. If you have been told to hold a dose, ask exactly when and how to restart.

If you miss a dose, follow the instructions on your patient card or ask your clinic. NHS guidance says never to take two doses together to make up for a missed one. The American College of Rheumatology notes that methotrexate rarely causes liver problems and that most people do not have side effects.

Bring your monitoring booklet or recent results to the appointment.

• How far above the lab's range is my ALT, and how does it compare with my earlier results?
• Is this a one-off rise or a trend, and when will it be repeated?
• Could another medicine, supplement, alcohol or a recent illness explain it?
• Do I need any other tests, such as a scan or hepatitis tests?
• Should I keep taking methotrexate and folic acid as before while we wait for results?
• What alcohol limit, if any, applies to me?
• Who should I call if I get symptoms between blood tests?

On SameCase, patients and verified doctors share de-identified cases. Seeing how others recorded liver test changes on methotrexate, along with their dates, other medicines and alcohol use, can help you organise your own history and questions. We do not diagnose, and another person's case cannot predict yours. Take your questions to your own care team.