Precautions and warnings

People with liver or kidney problems, bone marrow issues, older adults, or newborns should use caution. Be careful if you have ulcers or other digestive tract disorders. Regularly check blood counts, kidney and liver function, and watch for digestive system side effects.

Drug Interactions

**Folic acid and similar drugs may work less effectively.**

**Serious Risk:** Some medicines can make toxicity worse if used together, including:
- NSAIDs and salicylates
- Probenecid
- Certain penicillins
- Aminoglycoside antibiotics (like neomycin and paromomycin)
- Sulfonamides (like sulfafurazole and sulfamethoxazole)
- Co-trimoxazole or trimethoprim
- Drugs that can harm the kidneys (like cisplatin)
- Ciclosporin
- Etretinate

Taking this medicine with fluorouracil can increase their combined effects.
It can also increase how much mercaptopurine your body absorbs.

This drug may lower the level of valproate in your blood.
It may also have lower levels in your blood if taken with colestyramine, but higher levels if taken with omeprazole.

Contraindications

Do not use in people with severe kidney or liver problems, existing serious bone marrow issues (especially those with psoriasis or rheumatoid arthritis), alcoholic liver disease, AIDS, existing blood disorders, during pregnancy (for psoriasis or rheumatoid arthritis patients), or while breastfeeding.

Mode of actions

Methotrexate is a medicine that blocks the use of folic acid in the body, which is needed to make DNA. It permanently attaches to an enzyme called dihydrofolate reductase. By doing this, it stops the production of certain important chemicals (reduced folates and thymidylate synthetase), which are needed to make parts of DNA (purines and thymidylic acid). As a result, methotrexate prevents cells from making new DNA.

Dosage & Administration

Adult: PO Burkitt's lymphoma 10-25 mg/day for 4-8 days, repeat after 7-10 days. Choriocarcinoma 15-30 mg/day for 5 days, repeat after an interval of at least 1 wk for 3-5 courses. Mycosis fungoides 2.5-10 mg/day to induce remission. Rheumatoid arthritis 7.5 mg once wkly, adjust if needed. Up to 20 mg/wk. Crohn's disease 12.5-22.5 mg once wkly for up to 1 yr.

PO/IV/IM Psoriasis 10-25 mg once wkly, adjust subsequent doses if needed. IV Osteosarcoma 12-15 g/m2 as infusion, followed by folinic acid. Breast cancer 10-60 mg/m2 often w/ cyclophosphamide and fluorouracil. Advanced lymphosarcoma Up to 30 mg/kg, followed by folinic acid rescue. Acute lymphoblastic leukaemia Maintenance: 2.5 mg/kg every 14 days.

PO/IM Acute lymphoblastic leukaemia Maintenance: 15 mg/m2 1-2 times/wk w/ other agents. IM Choriocarcinoma 15-30 mg/day for 5 days. Repeat after at least 1 wk for 3-5 courses. Mycosis fungoides 50 mg/wk in 1-2 divided doses. Crohn's disease 25 mg once wkly for 16 wk. Maintenance: 15 mg/wk. Intrathecal Meningeal leukaemia 12 mg/m2 (Max: 15 mg) once wkly for 2-3 wk, then once mthly.

Renal impairment:
CrCl (ml/min)
61-80 75% of dose
51-60 70% of dose
10-50 30-50% of dose
5 mg/dl: Avoid use.

Pregnancy & Lactation

This medicine must not be used during pregnancy. It can be absorbed through the skin and lungs caused can damage your unborn child’s organs and cause congenital disabilities. Strict two effective types of birth control starting one month before and during treatment and for three years after stopping this medicine. Discuss with your doctors if you are not sure which types of birth control are effective for you. You must need to take pregnancy tests regularly during your treatment with this medicine and for at least three years after taking this medicine. If it seems that you do become pregnant stop taking this medicine and call your doctor immediately. If you really become pregnant, miss a menstrual period, or have sex without using two forms of birth control. In some cases, your doctor can prescribe emergency contraception to prevent pregnancy. People on this medicine should not donate blood during the treatment and for three years afterward.

This medicine is also contraindicated breast milk. Breastfeeding is not recommended while using this medication and for three years afterward.

Pack Size & Price