The short answer
- Tablets (2.5 mg, 10 mg): room temperature, below 25 °C, in the original pack. No fridge needed.
- Pre-filled pens and syringes (Metoject, Otrexup, Rasuvo, others): most are stored below 25 °C and must not be frozen; a few products differ, so read your leaflet.
- Weekly, not daily: for arthritis, psoriasis and similar conditions, methotrexate is taken once a week on the same day.
Storage by product
| Form |
Examples |
Storage |
| Tablets |
Methoblastin (AU), Maxtrex (UK), generic 2.5 mg and 10 mg |
Below 25 °C, dry, protected from light |
| Pre-filled pen |
Metoject PEN, Otrexup, Rasuvo, RediTrex |
Usually below 25 °C, in the carton; don’t freeze; don’t refrigerate unless the leaflet says so |
| Pre-filled syringe |
Metoject syringe, Methotrexate injection |
As above; check the leaflet |
| Oral solution |
Jylamvo, Xatmep |
Varies by brand: some are kept in the fridge before opening; check the label |
| Vials (hospital/clinic) |
Methotrexate injection |
Room temperature, protected from light |
If a pen or syringe has frozen, or the liquid looks cloudy or contains particles, don’t use it; ask your pharmacist for a replacement. Travelling with methotrexate in hot climates, keep it in hand luggage and out of direct sun. General storage rules are in our guide to taking medicines correctly.
The once-weekly rule
For rheumatoid arthritis, psoriasis, psoriatic arthritis and Crohn’s disease, methotrexate is given once a week, typically 7.5–25 mg. Taking that dose every day, instead of weekly, can cause serious bone-marrow, liver and gut toxicity and has caused deaths worldwide. To prevent mistakes:
- Choose a fixed day and write it on the pack and in your diary.
- Use one tablet strength only (usually 2.5 mg), to avoid mixing up 2.5 mg and 10 mg tablets.
- Take folic acid as prescribed, on a different day from methotrexate.
- Keep your blood test schedule (blood count, liver and kidney function).
- If you miss your dose by up to two days, take it then; if later, ask your team.
Took methotrexate on consecutive days by mistake? Contact a poisons information centre (Australia 13 11 26, US 1-800-222-1222, UK NHS 111) or your rheumatology team the same day, even if you feel well. An antidote (folinic acid) works best when started early.
Handling methotrexate safely
- Wash your hands after handling tablets; carers who are pregnant or planning pregnancy should wear gloves or avoid handling them.
- Don’t split or crush tablets unless your pharmacist advises it.
- Put used pens and syringes in a sharps container and return it as your pharmacy or council advises.
- Methotrexate must be stopped well before trying to conceive (for both women and men, as advised) and is not used in pregnancy.
Interactions to know
Trimethoprim and co-trimoxazole (Bactrim) can make methotrexate dangerously toxic and are usually avoided. Regular NSAIDs, some proton pump inhibitors at high doses and some other medicines can raise methotrexate levels; occasional ibuprofen at normal doses is often allowed with low-dose weekly methotrexate, but ask your team. Limit alcohol because of liver risk. See our guide to combining medicines.
Frequently asked questions
Can I keep my methotrexate pen in the fridge?
Most pens are meant for room temperature (below 25 °C). Refrigeration isn’t normally needed, and freezing damages them. Follow the specific leaflet for your brand.
What if my methotrexate tablets got warm?
Brief exposure to warmth, for example a day in a warm room, isn’t usually a problem. Tablets left in a hot car for long periods, or that look changed, should be replaced.
Does methotrexate expire?
Yes; use it before the expiry date on the pack and return expired or unwanted methotrexate to a pharmacy rather than putting it in household rubbish.
Sources and further reading
CanforaMedicine Guide
