Methotrexate in later life: blood tests, infections, vaccines and safety (UK guide)

Name: Methotrexate in Later Life: Safety Checks (UK) | LWA
Creator: Louis Maxwell

Written by Louis Maxwell — First Contact Practitioner, HCPC PH128483.

Clinical review status: not yet recorded

Methotrexate is a common and usually well-tolerated medicine for rheumatoid arthritis and other inflammatory arthritis, and age alone is not a reason to avoid it. In later life the main safety habits are: take it once a week on the same day (never daily), keep every blood test appointment, because the tests check your blood count, liver and kidneys, tell your team straight away about signs of infection such as a high temperature or sore throat, have the vaccines you are invited for and say you take methotrexate, and check with a pharmacist before taking any new medicine. Never change your…

This guide is about taking methotrexate safely in later life — the weekly routine, blood tests, infections, vaccines and other medicines. It does not give doses: always follow your prescription, the leaflet and your rheumatology team. For how methotrexate works, see DMARDs explained; for coping with sickness, mouth ulcers and tiredness, see managing methotrexate side effects. For how rheumatoid arthritis itself is checked over the years, see RA monitoring in later life.

Once a week, on the same day

For arthritis, methotrexate is taken once a week, on the same day each week. The medicines regulator, the MHRA, warns that taking it daily by mistake can cause serious and sometimes fatal harm, and these mix-ups are more likely when someone takes lots of other tablets, or when care changes hands, for example on a hospital admission. Simple habits help:

Agree your methotrexate day with your team and write it on the box and on the patient card that comes with the medicine
Carry the card and show it to anyone who treats you who does not know your usual care, such as a hospital doctor or out-of-hours service
Store methotrexate away from the medicines you take every day. If you use a pill organiser or your pharmacy prepares blister packs, ask the pharmacist how to keep the weekly medicine clearly separate
Folic acid is often prescribed alongside methotrexate to reduce side effects. It is not taken on the same day as methotrexate — follow the days your team gives you
If you forget, the NHS advises taking it as soon as you remember the next day or the day after; if it is more than 2 days late, contact your doctor or clinic. Never take 2 doses together

If you think you, or the person you care for, have taken more than prescribed or taken it daily instead of weekly, contact NHS 111 straight away. If you need to go to A&E, do not drive yourself, and take the packet and your other medicines with you.

Why the blood tests matter

Methotrexate can affect your blood cells and liver, and it is cleared by the kidneys, so regular blood tests are part of taking it safely. The NHS says that when you start, you will usually have blood tests to check your blood, liver and kidneys every 1 to 2 weeks; once the dose is settled and working, this usually drops to every 2 to 3 months for as long as you take it. Your team may change your dose based on the results — that decision is theirs, not yours.

Keep every appointment. If you cannot get there, tell your GP surgery or rheumatology team before the date rather than just missing it. Our guide to getting blood tests done when travel is hard has practical options
Keep your record. You will usually be given a booklet or app to record your dose and results. Bring it to appointments
Know who looks after the results. Often the hospital starts methotrexate and your GP takes over prescribing and blood tests once you are stable. Ask who will contact you if a result is not right
Alcohol and test day. Alcohol is also processed by the liver. NRAS suggests avoiding drinking the night before a blood test, as it can affect the results. Ask your team what is sensible for you; see arthritis and alcohol

Infections and sick days: ask, do not guess

Methotrexate calms the immune system, so infections can be more likely and sometimes more serious. The NHS advises telling your doctor if you think you are getting a sore throat or have a high temperature. Arthritis UK advises that if you get an infection or are prescribed antibiotics, you ask your nurse specialist or doctor whether it affects your weekly methotrexate. Many teams have a sick-day plan — ask for yours before you need it, and write it down.

Do not decide alone whether to skip or restart a dose when you are unwell. Phone your rheumatology advice line, GP or pharmacist and follow what they say
Tell every prescriber you take methotrexate, including out-of-hours and urgent care. Some antibiotics, including trimethoprim and co-trimoxazole, must not be taken with methotrexate
Older people do not always get a high temperature. New confusion, being much more unsteady, or simply being far less well than usual can be the first sign of an infection such as a urine infection or chest infection
Chickenpox and shingles: contact your doctor urgently if you develop either, or are in contact with someone who has them
Being sick or having diarrhoea: take small, frequent sips of water and contact your team if it does not settle, because dehydration can affect how your kidneys clear the medicine

Sepsis is a medical emergency. Call 999 or go to A&E if someone is confused, has slurred speech or is not making sense, has blue, grey, pale or blotchy skin, lips or tongue, a rash that does not fade when you press a glass on it, or is struggling to breathe.

Vaccines while taking methotrexate

The NHS advises having the vaccines you are invited for and telling the person giving them that you take methotrexate, because some vaccines may not be suitable. In general:

Flu: the yearly flu injection is recommended; the nasal spray is a live vaccine and is not used for adults taking methotrexate. See the flu jab and arthritis
Pneumococcal: a one-off injection that protects against a serious kind of chest infection; it is not live
Shingles: the shingles vaccine used for people with a weakened immune system is not live. See shingles vaccine and arthritis medicines
COVID-19: the vaccines are not live and are generally recommended — check your eligibility with your GP surgery
Live vaccines (for example some travel vaccines) usually need to be avoided — always ask your rheumatology team first

Vaccines for the people you live with can help protect you too. Our vaccines on DMARDs and biologics guide explains more.

Other medicines, supplements and painkillers

Methotrexate interacts with a number of common medicines. Arthritis UK advises not taking anti-inflammatory painkillers such as ibuprofen, or aspirin at painkiller strength, including cold and flu remedies that contain them, without speaking to your doctor first. Herbal remedies and supplements can interact too — see turmeric and methotrexate. Before you buy or are prescribed anything new, tell the pharmacist you take methotrexate. For pain relief choices with age, see painkillers in later life, and ask for a medication review if you take several medicines.

Never change your dose yourself

It can take up to 12 weeks to notice methotrexate working, and the NHS says it is important to keep taking it even if you do not feel different at first. If side effects bother you, or you are worried about taking it as you get older, talk to your team — they can change the dose, the form (tablets, liquid or injection) or the medicine. Stopping or cutting down on your own risks a flare. See stopping arthritis medicines safely.

When to get help

The NHS says to tell your doctor or call NHS 111 straight away if you get:

yellowing of the whites of the eyes or the skin
a cough that will not go away, chest pain, or new breathlessness
swollen hands, ankles or feet, or a change in how often you pee
a high temperature, feeling hot, cold or shivery, muscle aches or a sore throat
bleeding gums, blood in your pee, vomiting blood or unexplained bruising

Call 999 for signs of a serious allergic reaction, such as sudden swelling of the lips, mouth or throat or struggling to breathe, or for any signs of sepsis. You can report suspected side effects to the MHRA Yellow Card scheme.

For family and carers

Know the methotrexate day and where the patient card is
Help keep blood test dates in the diary and arrange transport early
Watch for quiet signs of infection — confusion, not eating, being more unsteady — and phone for advice early
Keep an up-to-date list of all medicines to show any doctor, especially out of hours

Frequently asked questions

Should I stop methotrexate when I have a cold or infection?

Do not stop or skip it on your own. Ask your rheumatology advice line, GP or pharmacist — they will tell you whether to pause your weekly dose and when to restart, based on how unwell you are.

Can I have the flu jab while taking methotrexate?

Yes, the flu injection is recommended. Tell the person giving it that you take methotrexate, as the nasal spray version is a live vaccine and is not suitable.

Why do I still need blood tests after years on methotrexate?

Because problems with the blood count, liver or kidneys can develop at any time, often without symptoms, and kidney function can change with age. Regular tests let your team spot a change early.

Sources and further reading

Educational information for people in the United Kingdom — not a diagnosis or personal medical advice. Charity no. 1218461. Pending clinical review. Living With Arthritis is an independent charity and is not part of Arthritis UK (formerly Versus Arthritis) or the NRAS. Everyone's situation is different, so always follow the advice of your own GP, pharmacist, rheumatology nurse or rheumatologist, and never stop or change a prescribed medicine yourself. If you feel very unwell, call 999 or go to A&E. For urgent advice, contact NHS 111.

Continue with related help

DMARDs explained — how methotrexate slows rheumatoid arthritis
Methotrexate side effects — practical tips
RA monitoring in later life — tests, reviews and what to report
Vaccines on DMARDs — what is safe and when
Getting to blood tests — when travel is hard
Medication reviews — a pharmacist check of everything you take
Rheumatoid arthritis — condition guide

Last updated 2026-10-22. This is general information, not a substitute for personalised medical advice.