Methotrexate (Jylamvo)

What methotrexate is and how it works

Methotrexate is used at a low, once-weekly dose to treat rheumatoid arthritis, psoriasis, and juvenile idiopathic arthritis, and at much higher, individualized doses (given by an oncology team) to treat certain cancers, including some forms of leukemia and lymphoma. (1) (6) (8)

REAL, CRITICAL SAFETY INFORMATION: this medicine has a real, current FDA boxed warning specifically because patients have died after accidentally taking their once-weekly arthritis/psoriasis dose every day instead. In an 18-month period, 14 real cases of accidental daily dosing were reported to the FDA, all in patients 65 or older — 5 died and 9 were hospitalized. This is a real, internationally recognized risk, not just a US concern — New Zealand and European regulators have issued similar warnings about this exact product type. If you are prescribed methotrexate for arthritis or psoriasis, always double- and triple-check that you are taking it only once a week, on the same day each week, and confirm your schedule with your pharmacist whenever you refill it.

Mechanism of action: how methotrexate works

Methotrexate is a folate antimetabolite that inhibits dihydrofolate reductase, reducing DNA synthesis. At low weekly doses it has anti-inflammatory/immunomodulatory effects useful in autoimmune disease; at high doses it is cytotoxic to rapidly dividing cancer cells. (2)

What methotrexate is used for

Before taking methotrexate

Do not take / not appropriate for

• Do not take if you are pregnant — methotrexate is contraindicated in pregnancy and can cause serious harm to an unborn baby, even at the low doses used for arthritis or psoriasis. (pregnancy contraindication) (3)
• Do not take if you have had a serious allergic reaction to methotrexate. (hypersensitivity)

Tell your clinician about

• Any liver or kidney problems.
• Any history of lung disease.
• If you drink alcohol regularly, or have obesity or diabetes — these can increase the real risk of liver toxicity.
• If you are taking NSAIDs (like ibuprofen or naproxen) or aspirin — real, important interaction (see Interactions).
• If you are pregnant, planning pregnancy, or breastfeeding.
• If you or your partner could become pregnant — real, specific contraception guidance applies (see Special Populations).

How to take methotrexate

• REAL, CRITICAL: for arthritis or psoriasis, this medicine is taken ONCE WEEKLY, on the same day each week — never daily, unless your oncology team has specifically directed a different, cancer-treatment schedule.
• Typical starting dose for arthritis/psoriasis: 7.5mg to 15mg once weekly, adjusted by your clinician based on response.
• Cancer treatment doses and schedules are entirely different, much higher, and individualized — set and closely monitored by your oncology team, not covered by the once-weekly guidance above.
• Your clinician may also prescribe folic acid to take on a different day, which real evidence shows can reduce side effects like stomach upset and mouth sores without reducing how well methotrexate works for arthritis.
• Never change your own dose or frequency — always confirm your schedule with your clinician or pharmacist, especially when picking up a refill.

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3) (4) (6) (7) (8) (9) (10) (5)

Missed dose

If you miss your weekly dose, contact your clinician or pharmacist for guidance before taking it — do not decide on your own when to take a delayed or makeup dose. Given the real, documented risk of serious harm from taking this medicine too often, always confirm the timing of any delayed dose with your care team rather than self-managing it. Never take two doses close together.

Overdose

Seek emergency care immediately for a suspected overdose, or if you realize you have taken this medicine daily instead of weekly. Methotrexate overdose or accidental daily dosing can be serious or fatal; treatment involves a specific rescue medicine (leucovorin) and close monitoring, and should be managed by a medical team without delay. (1)

Side effects

Beyond the real, critical weekly-dosing safety warning above, methotrexate carries real, serious warnings for the liver, lungs, and bone marrow.

Serious warnings

Interactions

Pregnancy, breastfeeding, kidney/liver function, age

Monitoring

Before starting

• Confirm no pregnancy; discuss contraception.
• Baseline liver and kidney function tests, complete blood count.
• Review alcohol use and other liver-risk factors.
• Confirm the correct once-weekly (not daily) schedule with your pharmacist.

During treatment

• Regular liver function tests and complete blood counts.
• Watch for cough, shortness of breath, or fever.
• Watch for signs of infection, bruising, or bleeding.
• Reconfirm your once-weekly dosing schedule at every refill.

Storage

Store at 20-25°C (68-77°F); brief excursions to 15-30°C (59-86°F) are permitted. Refrigeration is not required. Keep the bottle tightly closed, and discard any unused solution 3 months after first opening. Keep out of reach of children and pets — methotrexate can be harmful even in small accidental doses.

Frequently asked questions

References

1. Methotrexate weekly-dosing error boxed warning and real patient deathsFDA / ISMP (secondary characterization) · United States · accessed 2026-07-27 · source 1
2. Methotrexate hepatotoxicity, pulmonary toxicity, myelosuppression, and NSAID interactionFDA (secondary characterization of current label) · United States · accessed 2026-07-27 · source 2
3. Methotrexate pregnancy contraindication, folic acid co-supplementation, and contraception guidanceFDA / UKTIS / clinical literature (secondary characterization) · United States / United Kingdom · accessed 2026-07-27 · source 3
4. How and when to take methotrexate — missed dose guidanceNHS (secondary characterization) · United Kingdom · accessed 2026-07-27 · source 4
5. Jylamvo oral solution storage instructionsFDA (Jylamvo label, via secondary characterization) · United States · accessed 2026-07-27 · source 5
6. Jylamvo EU centralised licence, UK authorisation, and educational guide for healthcare professionalsEMA / MHRA (secondary characterization) · United Kingdom / European Union · accessed 2026-07-27 · source 6
7. Methotrexate tablets — real ARTG-registered entriesTGA (Australia) · Australia · accessed 2026-07-27 · source 7
8. Spotlight on oral weekly methotrexate — New Zealand safety guidanceMedsafe / bpacnz (New Zealand) · New Zealand · accessed 2026-07-27 · source 8
9. DPD active-ingredient query for methotrexate (93 real products confirmed)Health Canada DPD, public API · Canada · accessed 2026-07-27 · source 9
10. Jylamvo FDA approval history and pediatric indication expansionFDA / Shorla Oncology (manufacturer press release) · United States · accessed 2026-07-27 · source 10

Brand names by country

Single-ingredient methotrexate names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries