Methotrexate

What is Methotrexate?

Methotrexate is a medicine that inhibits the metabolism of certain types of cells. It is used to treat certain cancers, rheumatoid arthritis (including polyarticular juvenile arthritis), and severe psoriasis.

What is the most important information I should know about Methotrexate?

Methotrexate can cause serious and life-threatening side effects. These side effects can be monitored by your doctor using simple medical tests before they become serious. Your doctor will monitor you when you are taking Methotrexate to check how it affects your body. Inform your doctor immediately of any side effects you experience while taking Methotrexate.

Methotrexate can cause birth defects or fetal death. If you are pregnant, or your partner is pregnant or plans to become pregnant, you should not take Methotrexate. Women should wait at least 1 menstrual cycle after stopping Methotrexate therapy before getting pregnant, and men should wait at least 3 months after stopping Methotrexate therapy before getting their partner pregnant. If you can become pregnant, you should have a pregnancy test before taking Methotrexate. Both men and women should use effective methods of birth control while taking Methotrexate.

You should stop taking Methotrexate and call your doctor right away if you experience diarrhea, mouth sores, a fever, dehydration, cough, bleeding, shortness of breath, any signs of an infection, or a skin rash. Your doctor may also prescribe a folate-containing medication to take in addition to Methotrexate to help reduce possible side effects.

Who should not take Methotrexate?

You should not take Methotrexate if you are pregnant or plan to become pregnant, are breastfeeding, have conditions that weaken your immune system, your bone marrow doesn't make enough blood cells, you have low platelet or white blood cell counts, serious anemia, drink alcohol, have chronic liver disease, or if you are allergic or have a hypersensitivity to Methotrexate.

What should I tell my doctor before I take the first dose of Methotrexate?

Tell your doctor if you are pregnant or your sexual partner is pregnant or plans to become pregnant.

Tell your doctor about all prescription, over-the-counter, and herbal medications you are taking before beginning treatment with Methotrexate. Also, talk to your doctor about your complete medical history, especially if you have kidney problems or are getting dialysis, liver problems, fluid in your stomach area, or if you have lung problems including fluid in your lungs.

What is the usual dosage?

The information below is based on the dosage guidelines your doctor uses. Depending on your condition and medical history, your doctor may prescribe a different regimen. Do not change the dosage or stop taking your medication without your doctor's approval.

Choriocarcinoma and similar trophoblastic diseases

Adults: The usual starting dose is 15-30 milligrams (mg) daily for 3 to 5 days. This is usually repeated 3-5 times with rest periods in between of 1 to several weeks.

Adults: Cutaneous T Cell Lymphoma

Adults: The usual dosage is 5-50 mg taken once weekly

Leukemia

Adults: The usual dose is 3.3 mg per square meter of body mass given once daily in combination with other medicines.

Adults: Lymphomas

Adults: The usual dose is 10-25 mg daily for 4 to 8 days, but may vary depending on the type or stage of lymphoma being treated.

Adults: Psoriasis, Rheumatoid Arthritis, and Juvenile Rheumatoid Arthritis

Adults: The usual starting dose includes a single dose of 7.5 mg taken once a week, or 2.5 mg taken every 12 hours for 3 doses once a week.

Adults: Polyarticular-Course Juvenile Rheumatoid Arthritis

Children: The usual starting dose is 10 mg per square meter of body mass taken once a week. Based on the response to this dosage, the doctor may increase the dose to 20-30 mg per square body meter taken once weekly.

How should I take Methotrexate?

Methotrexate should be taken exactly as prescribed by your doctor. You should not take more Methotrexate than prescribed.

For severe psoriasis, rheumatoid arthritis, and juvenile rheumatoid arthritis Methotrexate should be taken weekly, not every day. If you take too much Methotrexate, call your doctor immediately or go to the nearest emergency room.

What should I avoid while taking Methotrexate?

You should avoid getting pregnant or trying to become pregnant, breastfeeding, drinking alcohol, or receiving certain live vaccines.

What are possible food and drug interactions associated with Methotrexate?

If Methotrexate is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining Methotrexate with the following: chloramphenicol, nonabsorbable broad-spectrum antibiotics, nonsteroidal anti-inflammatory drugs, phenylbutazone, phenytoin, probenecid, salicylates, sulfonamides, tetracycline, penicillin-type antibiotics, theophylline, trimethoprim/sulfamethoxazole, and vitamins containing folic acid or its derivatives.

What are the possible side effects of Methotrexate?

Side effects cannot be anticipated. If any develop or change in intensity, tell your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking this drug.

Side effects may include: birth defects and fetal death; cancer of the lymphatic system (lymphoma); kidney damage; lower white cells, red cells, and platelets in your blood; liver damage; lung disease; opportunistic infections such as Pneumocystis carinii pneumonia; severe anemia; severe skin reactions and rashes; soft tissue and bone damage if you are getting radiation therapy at the same time you are taking Methotrexate

Can I receive Methotrexate if I am pregnant or breastfeeding?

Methotrexate should NOT be taken if you are pregnant, plan to become pregnant, or are breastfeeding. Men who are taking Methotrexate should not get their partners pregnant for at least 3 months after last taking Methotrexate.

What should I do if I miss a dose of Methotrexate?

If you forget to take a dose of Methotrexate, ask your doctor if and when you should take your next dose.

How should I store Methotrexate?

Methotrexate should be stored at room temperature.