methotrexate

Methotrexate interferes with the growth of certain cells of the body, especially cells that reproduce quickly, such as cancer cells, bone marrow cells, and skin cells.

Methotrexate is used to treat certain types of cancer of the breast, skin, head and neck, or lung. It is also used to treat severe psoriasis and rheumatoid arthritis.

Methotrexate is usually given after other medications have been tried without successful treatment of symptoms.

Methotrexate may also be used for purposes not listed in this medication guide.

Important information

Methotrexate is usually taken once or twice per week and not every day. You must use the correct dose for your condition. Some people have died after taking methotrexate every day by accident.

Do not use methotrexate to treat psoriasis or rheumatoid arthritis if you have liver disease (especially if caused by alcoholism), or a blood cell or bone marrow disorder.

Do not use methotrexate if you are pregnant or breast-feeding a baby.

Methotrexate can lower blood cells that help your body fight infections and help your blood to clot. You may get an infection or bleed more easily. Call your doctor if you have unusual bruising or bleeding, or signs of infection (fever, chills, body aches).

Methotrexate can cause serious or life-threatening side effects on your liver, lungs, or kidneys. Tell your doctor if you have upper stomach pain, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes), dry cough, shortness of breath, blood in your urine, or little or no urinating.

Before taking this medicine

You should not use this medicine if you are allergic to methotrexate. Do not use methotrexate to treat psoriasis or rheumatoid arthritis if you have:

• alcoholism, cirrhosis, or other liver disease;

• a blood cell disorder such as anemia (lack of red blood cells) or leukopenia (lack of white blood cells);

• a bone marrow disorder; or

• if you are breast-feeding a baby.

Methotrexate is sometimes used to treat cancer even when patients do have one of the conditions listed above. Your doctor will decide if this treatment is right for you.

To make sure methotrexate is safe for you, tell your doctor if you have:

• kidney disease;

• a folate deficiency;

• pneumonia or lung disease;

• stomach ulcers;

• any type of infection; or

• if you are receiving radiation treatments.

FDA pregnancy category X. Methotrexate can cause birth defects in an unborn baby. Do not use methotrexate to treat psoriasis or rheumatoid arthritis if you are pregnant. Tell your doctor right away if you become pregnant during treatment.

See also: Pregnancy and breastfeeding warnings (in more detail)

You may need to have a negative pregnancy test before starting this treatment.

Use birth control to prevent pregnancy while you are using methotrexate, whether you are a man or a woman. Methotrexate use by either parent may cause birth defects.

If you are a man, use a condom to keep from causing a pregnancy while you are using methotrexate. Continue using condoms for at least 90 days after your treatment ends.

If you are a woman, use an effective form of birth control while you are taking methotrexate, and for at least one cycle of ovulation after your treatment ends.

Do not give this medicine to a child without the advice of a doctor.

Older adults may be more likely to have side effects from this medication.

How should I take methotrexate?

Take methotrexate exactly as it was prescribed for you. Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.

You must use the correct dose of methotrexate for your condition. Methotrexate is sometimes taken once or twice per week and not every day. Follow the directions on your prescription label. Some people have died after taking methotrexate every day by accident. Ask your doctor or pharmacist if you have questions about your dosage or how often to take this medicine.

Use methotrexate regularly to get the most benefit. Get your prescription refilled before you run out of medicine completely.

Methotrexate can lower blood cells that help your body fight infections and help your blood to clot. Your blood will need to be tested often, and you may need an occasional liver biopsy. Your cancer treatments may be delayed based on the results of these tests.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Call your doctor for instructions if you miss a dose of methotrexate.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose of methotrexate can be fatal.

What should I avoid?

Methotrexate can pass into body fluids (including urine, feces, vomit, semen, vaginal fluid). Patients and caregivers should wear rubber gloves while cleaning up body fluids, handling contaminated trash or laundry or changing diapers. Wash hands before and after removing gloves. Wash soiled clothing and linens separately from other laundry.

Body fluids should not be handled by a woman who is pregnant or who may become pregnant. Use condoms during sexual activity to avoid exposure to body fluids.

Avoid exposure to sunlight or artificial UV rays (sunlamps or tanning beds), especially if you are being treated for psoriasis. Methotrexate can make your skin more sensitive to sunlight and your psoriasis may worsen.

Avoid drinking alcohol while taking methotrexate.

Methotrexate side effects

Get emergency medical help if you have any signs of an allergic reaction to methotrexate: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop using methotrexate and call your doctor at once if you have:

• dry cough, shortness of breath;

• diarrhea, vomiting, white patches or sores inside your mouth or on your lips;

• blood in your urine or stools;

• swelling, rapid weight gain, little or no urinating;

• seizure (convulsions);

• fever, chills, body aches, flu symptoms;

• pale skin, easy bruising, unusual bleeding, weakness, feeling light-headed or short of breath;

• liver problems - nausea, upper stomach pain, itching, tired feeling, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes); or

• severe skin reaction - fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain, followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling.

Common methotrexate side effects may include:

• vomiting, upset stomach;

• headache, dizziness, tired feeling; or

• blurred vision.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

See also: Side effects (in more detail)

Methotrexate dosing information

Usual Adult Dose of Methotrexate for Acute Lymphoblastic Leukemia:

Induction: 3.3 mg/m2/day orally or IM (in combination with prednisone 60 mg/m2).

Maintenance (during remission): 15 mg/m2 IM or orally twice a week.
Alternate remission dosing: 2.5 mg/kg IV every 14 days.

Usual Adult Dose of Methotrexate for Choriocarcinoma:

15 to 30 mg IM or orally daily for 5 days. Repeat courses 3 to 5 times with a rest period of greater than or equal to 1 week between courses, until any manifesting toxic symptoms subside.

Effectiveness of therapy is ordinarily evaluated by 24 hour quantitative analysis of urinary chorionic gonadotropin (hCG), which generally will return to normal or less than 50 intl units/24 hours usually after the third or fourth course and usually followed by a complete resolution of measurable lesions in 4 to 6 weeks. One to two courses of methotrexate after normalization of hCG is usually recommended.

Usual Adult Dose of Methotrexate for Trophoblastic Disease:

15 to 30 mg IM or orally daily for 5 days. Repeat courses 3 to 5 times with a rest period of greater than or equal to 1 week between courses, until any manifesting toxic symptoms subside.

Effectiveness of therapy is ordinarily evaluated by 24 hour quantitative analysis of urinary chorionic gonadotropin (hCG), which generally will return to normal or less than 50 intl units/24 hours usually after the third or fourth course and usually followed by a complete resolution of measurable lesions in 4 to 6 weeks. One to two courses of methotrexate after normalization of hCG is usually recommended.

Usual Adult Dose of Methotrexate for Lymphoma:

For Burkitt"s tumor in Stages I-II: 10 to 25 mg orally once a day for 4 to 8 days

Malignant lymphoma in Stage III: 0.625 to 2.5 mg/kg orally daily as a part of combination chemotherapy.

Treatment in all stages usually consists of several courses of the drug interposed with 7 to 10 day rest periods.

Usual Adult Dose for Meningeal Leukemia:

12 mg/m2 intrathecally every 2 to 5 days until the cell count of the CSF returns to normal. At this point, one additional dose is advisable. Administration at intervals of less than 1 week may result in increased subacute toxicity.

Usual Adult Dose for Mycosis Fungoides:

2.5 to 10 mg PO daily or 50 mg IM once a week or 25 mg IM twice a week.

Usual Adult Dose for Osteosarcoma:

Initial Dose: 12 g/m2 intravenously as a 4 hour infusion (in combination with other chemotherapeutic agents). If this dose is not adequate to achieve a peak serum concentration of 1000 micromolar at the end of the infusion, the dose may be increased to 15 g/m2.

Treatments may occur at 4, 5, 6, 7, 11, 12, 15, 16, 29, 30, 44, and 45 weeks after surgery.

If the patient is vomiting or unable to tolerate oral medication, leucovorin should be added to this regimen at the same dose and schedule as the methotrexate.

Usual Adult Dose for Psoriasis:

Single Dose: 10 to 25 mg/week orally, IM, or IV until adequate response is achieved.
Divided Dose: 2.5 mg orally, IM, or IV every 12 hours for 3 doses once a week.
Maximum weekly dose: 30 mg.

Usual Adult Dose for Rheumatoid Arthritis:

Single dose: 7.5 mg orally weekly.
Divided dose: 2.5 mg orally every 12 hours for 3 doses once a week.
Maximum weekly dose: 20 mg.

Usual Adult Dose for Neoplastic Diseases:

I.V.: Range is wide from 30-40 mg/m2/week to 100-12,000 mg/m2 with leucovorin rescue

Usual Pediatric Dose for Acute Lymphocytic Leukemia:

100 mg/m2 over 1 hour followed by a 35 hour infusion delivering 900 mg/m2/day.

Usual Pediatric Dose for Dermatomyositis:

15 to 20 mg/m2 orally once weekly.

Usual Pediatric Dose for Meningeal Leukemia:

less than 4 months: 3 mg/dose intrathecally.
greater than or equal to 4 months less than 1 year: 6 mg/dose intrathecally.
greater than or equal to 1 year less than 2 years: 8 mg/dose intrathecally.
greater than or equal to 2 years less than 3 years: 10 mg/dose intrathecally.
greater than or equal to 3 years: 12 mg/dose intrathecally.

The dose may be administered every 2 to 5 days until CSF counts return to normal followed by a dose administered once weekly for 2 weeks and monthly thereafter. Administration at intervals of less than 1 week may result in increased subacute toxicity.

Usual Pediatric Dose for Neoplastic Diseases:

7.5 to 30 mg/m2 IM or orally every 2 weeks.
Alternate dosing: 10 to 18,000 mg/m2 IV bolus or continuous infusion over 6 to 42 hours.

Usual Pediatric Dose for Rheumatoid Arthritis:

5 to 15 mg/m2 IM or orally once weekly.

Usual Pediatric Dose for Solid Tumors:

less than 12 years: 12000 mg/m2 IV.
greater than or equal to 12 years: 8000 mg/m2 IV.
Maximum dose: 18 grams.

What other drugs will affect methotrexate?

Many drugs can interact with methotrexate. Not all possible interactions are listed here. Tell your doctor about all your medications and any you start or stop using during treatment with methotrexate, especially:

• azathioprine;

• leucovorin;

• phenytoin;

• probenecid;

• theophylline;

• an antibiotic or sulfa drugs;

• isotretinoin, retinol, tretinoin;

• NSAIDs (non-steroidal anti-inflammatory drugs) - ibuprofen (Advil, Motrin), naproxen (Aleve), celecoxib, diclofenac, indomethacin, meloxicam, and others; or

• salicylates - aspirin, Nuprin Backache Caplet, Kaopectate, KneeRelief, Pamprin Cramp Formula, Pepto-Bismol, Tricosal, Trilisate, and others.

This list is not complete and many other drugs can interact with methotrexate. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Give a list of all your medicines to any healthcare provider who treats you.