Methotrexate — once weekly, never daily
Content date: 15 November 2026
For people prescribed low-dose methotrexate for an inflammatory condition, including selected Crohn’s disease. It is used once a week, never daily. Cancer-treatment schedules are outside this guide.
Your next step
Write your weekly day, exact prescribed amount, folic-acid schedule and next blood-test date with the team. Resolve unclear instructions before taking a dose.
Get urgent help: An extra dose or daily instead of weekly use needs immediate medical assessment, even if you feel well: do not take more, bring the pack and contact emergency care now. Seek emergency help for breathing difficulty, face/throat swelling, severe illness or significant bleeding.
Why might it be prescribed?
- It changes immune activity to help control inflammation. It is an option for selected Crohn’s disease and sometimes accompanies another IBD treatment; it is not usual ulcerative-colitis treatment on its own. Benefits take time, so keep the agreed follow-up.
Using the medicine safely
- Take the prescribed dose on the same named day each week. Tablet strengths and injection devices differ: confirm the total milligrams and tablet count or injection amount, rather than copying someone else’s plan. Ask for injection training if needed.
- Use the pack instructions for swallowing or injecting. If a dose is missed or you are unsure whether you took it, ask the pharmacist or team; do not double, guess or add an extra dose. Store it separately from daily medicines.
Folic acid and blood tests
- Take the folic acid prescribed with methotrexate to reduce some side effects. Its dose and days have a separate written schedule; do not add supplements or change the schedule yourself.
- Blood count, liver and kidney tests are needed before treatment and regularly afterward, often more frequently when starting or changing dose. The team checks relevant infections, vaccinations and pregnancy status. Keep your next test date even when you feel well.
Other medicines and infection
- Show every prescriber and pharmacist your methotrexate card. Trimethoprim and co-trimoxazole can cause a dangerous interaction and should be avoided unless the specialist explicitly manages their use. Check antibiotics, ibuprofen and other anti-inflammatory painkillers, acid medicines, herbal products and supplements before starting them.
- Ask the team before live vaccines. Tell them promptly about significant infection, vomiting or dehydration and ask what to do before the next dose. Disclose liver or kidney disease and alcohol use; alcohol adds to liver risk.
Possible side effects
- Nausea, tiredness or mild stomach upset can occur; not everyone develops them. Prescribed folic acid and monitoring help. Report persistent effects so the team can adjust the plan.
- Less common but important problems can affect blood cells, liver or lungs. Prompt assessment is needed for the warning symptoms below. A normal earlier test does not replace the next scheduled check.
Pregnancy, planning a family and breastfeeding
- Methotrexate must not be used during pregnancy for inflammatory disease because it can harm the unborn baby. If pregnancy is suspected or confirmed, contact the prescribing team immediately before taking another dose.
- Effective contraception is required for people who can become pregnant during treatment and for a specified interval afterward. Agree the exact interval for your product before stopping contraception. Men planning fatherhood should also discuss product-specific and specialist advice. Breastfeeding needs a specialist plan before treatment; do not assume spacing a feed after a dose makes it safe.
Storage and handling
- Keep the original labelled pack, away from children, heat and moisture, and follow its temperature limit. Do not leave it in a car. Keep weekly tablets apart from daily medicines and return unused medicine to a pharmacy; use the supplied sharps arrangements for injections.
My weekly plan — complete with the treating team
| What to confirm | My written plan |
|---|---|
| Methotrexate day (write the full weekday) | ................................ |
| Product / tablet or injection / strength | ................................ |
| Total prescribed weekly dose in mg | ................................ |
| Number of tablets OR prescribed injection amount | ................................ |
| Folic-acid dose and separate schedule | ................................ |
| Next blood test and who reviews it | ................................ |
| Team contact / missed-dose instructions | ................................ |
- Before the weekly dose: check the written day, product, strength and prescribed amount.
- On that day: take or inject only the prescribed weekly dose; record that it was taken.
- On other days: no additional methotrexate. Use folic acid only on its prescribed schedule.
- Before the next dose: follow any instructions about illness, overdue blood tests or changed medicines.
This checklist records an existing prescription; it does not calculate a dose or authorise treatment changes.
When to get help
An extra dose or daily instead of weekly use needs immediate medical assessment, even if you feel well: do not take more, bring the pack and contact emergency care now. Seek emergency help for breathing difficulty, face/throat swelling, severe illness or significant bleeding.
Contact the team the same day for fever, mouth ulcers, unexplained bruising, yellow eyes/skin, a persistent new cough, reduced urine or ongoing vomiting; obtain advice before the next dose.
Related guides
Sources
MHRA: preventing weekly methotrexate dosing errors
NHS: taking methotrexate and folic acid
NHS Specialist Pharmacy Service: methotrexate monitoring
NHS Specialist Pharmacy Service: methotrexate interactions
NHS: methotrexate side effects
Methotrexate: official product information and reproductive precautions