Methotrexate remains the first drug reached for in rheumatoid arthritis and several other inflammatory conditions, and it is the drug people are most anxious about starting. Much of that anxiety comes from reading about the doses used in cancer treatment, which are many times higher than the doses used here.
What it does, and why it is worth taking
Inflammatory arthritis damages joints permanently, and the damage happens early. Painkillers make the joints feel better without changing that. Methotrexate belongs to a group of drugs that alter the disease itself: it dampens the immune activity driving the inflammation, so the joints stop being eroded.
The aim is not simply to feel better. The aim is that in five years the joints still work.
Once a week, not once a day
This is the single most important practical point. Methotrexate is taken once a week, on the same day each week. Taking it daily by mistake is dangerous. Pick a day that is easy to remember, write it down, and set a reminder on your phone.
Many people take it on a Friday or Saturday evening, so that any tiredness the following day falls on a rest day.
It takes time
Methotrexate does not work like a painkiller. Most people notice the first improvement somewhere between six and twelve weeks, and the full effect can take three to six months. The dose is usually started low and increased over the first couple of months.
Because of that delay, a steroid or an anti-inflammatory is often prescribed alongside it at the start, to keep symptoms manageable while the methotrexate takes hold. That cover is then withdrawn.
Stopping methotrexate at four weeks because "it is not working" is the commonest avoidable mistake.
Folic acid is not optional
Folic acid taken on the days you are not taking methotrexate substantially reduces nausea, mouth ulcers and abnormal liver blood tests. Take it exactly as prescribed. If nausea is still a problem, tell the clinic — the dose or the timing can be adjusted, and switching from tablets to a weekly injection often solves it completely.
The blood tests, and why they are frequent at first
Blood tests check the blood counts and the liver. They are done every two to four weeks at the start, and then, once the dose is stable and the results are steady, every eight to twelve weeks.
These tests are not a formality. They pick up the small number of problems that can occur, at a stage when the only action needed is a dose change. Missing them is the main reason methotrexate has to be stopped altogether.
Alcohol, pregnancy and infection
- Alcohol puts additional load on the liver. Keep intake low, and discuss what is reasonable for you rather than guessing.
- Pregnancy. Methotrexate must not be taken during pregnancy, and it must be stopped in advance by both women and men who are planning to conceive. Reliable contraception is needed while taking it. If pregnancy is anywhere in your plans, raise it early — there are effective alternatives that are safe in pregnancy.
- Infection. Methotrexate mildly increases infection risk. If you develop a fever or a significant infection, hold the weekly dose and contact the clinic.
What to report straight away
- Fever, or an infection that is not settling
- A persistent dry cough or new breathlessness
- Mouth ulcers that are painful enough to affect eating
- Yellowing of the eyes or skin
- Unusual bruising or bleeding
The realistic picture
Most people tolerate methotrexate well and stay on it for years. A minority get nausea or tiredness for a day after the dose, which usually improves with folic acid, a change of timing, or a switch to the injectable form. A small number cannot take it at all, and there are now several good alternatives.
The decision is always made with you, with the reasoning explained, and it can be revisited at any point.
This article is general information and does not replace a consultation.