Drug
Methotrexate
Pronounced
"METH-oh-TREX-ate"
Uses
Methotrexate is used to treat severe psoriasis that has not responded to other treatments or rheumatoid arthritis. It may also be used to treat a certain type of arthritis in children (polyarticular juvenile idiopathic arthritis - pJIA). Methotrexate belongs to a class of drugs known as antimetabolites. It works by blocking the immune system from attacking healthy tissue.
Early treatment of rheumatoid arthritis with methotrexate helps to reduce further joint damage and to preserve joint function.
Warning
Methotrexate has rarely caused serious (sometimes fatal) side effects. This medication should be used only to treat severe diseases caused by an overactive immune system (such as psoriasis, rheumatoid arthritis).
Methotrexate has caused birth defects and death in unborn babies. Women must avoid becoming pregnant while using this medication. Pregnant women who have psoriasis or rheumatoid arthritis must not use methotrexate. (See also Precautions section.)
If you have kidney problems or excess body water (ascites, pleural effusion), you must be closely monitored and your dose may be adjusted or stopped by your doctor.
Methotrexate (usually at high dosages) has rarely caused severe (sometimes fatal) blood/bone marrow problems (decreasing your body's ability to fight infections) and stomach/intestinal disease (such as bleeding) when used at the same time as non-steroidal anti-inflammatory drugs (NSAIDs such as indomethacin, ketoprofen). NSAIDs should not be used with high-dose methotrexate. Caution is advised if you also take aspirin. NSAIDs/aspirin may be used with low-dose methotrexate such as for the treatment of rheumatoid arthritis if directed by your doctor. If your doctor has told you to take low-dose aspirin to prevent heart attack or stroke (usually 81-162 milligrams a day), you should keep taking the aspirin unless your doctor tells you not to. Ask your doctor or pharmacist for more details on the safe use of these drugs (such as close monitoring by your doctor, keeping the same doses of NSAIDs).
In rare instances, this drug may also cause liver problems when it is used for long periods of time. If you are using methotrexate long term, a liver biopsy is usually recommended.
Methotrexate use has rarely caused serious (sometimes fatal) side effects, such as lung problems, lung infections (Pneumocystis jiroveci pneumonia), skin reactions, diarrhea, and mouth sores (ulcerative stomatitis). (See also Side Effects section.)
Lumps (tumors/abnormal growths) may very rarely appear during methotrexate use. The drug must be stopped and treatment may be needed. Tell your doctor right away if new lumps/growths occur.
When used to treat tumors, methotrexate sometimes causes side effects due to the rapid destruction of cancer cells (tumor lysis syndrome). To lower your risk, drink plenty of fluids unless your doctor directs you otherwise. Also, your doctor may prescribe an additional medication. Tell your doctor right away if you have symptoms such as irregular heartbeat, low back/side pain, signs of kidney problems (such as pink/bloody urine, change in the amount of urine, painful urination), or muscle spasms/weakness.
When this medication is used with radiation treatment, it may rarely increase the risk of tissue and bone damage. Discuss the risks and benefits of your treatment with your doctor.
Other Uses
This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional.
This medication may also be used for lupus, psoriatic arthritis, and Crohn's disease.
How to Use This Medication
Read the Patient Information Leaflet and Instructions for Use if available from your pharmacist before you start using methotrexate and each time you get a refill. Ask your health care professional how to prepare and use this medication. If you have any questions, ask your doctor or pharmacist.
Inject this medication under the skin as directed by your doctor, usually once a week. The injection is given in the thighs or abdomen. Some brands may also be given in the upper arms. The dosage is based on your medical condition and response to treatment.
Before using, check this product for particles or discoloration. If either is present, do not use the liquid. Before injecting each dose, clean the skin you are going to inject into (the injection site) with rubbing alcohol. Change the injection site each time to lessen injury under the skin. Do not inject into skin that is red, swollen, or bruised, or into areas with scars/stretch marks. To lessen bruising, do not rub the injection site after a shot. Learn how to store and discard medical supplies safely.
Use this medication regularly to get the most benefit from it. To help you remember, use it on the same day each week. Mark your calendar with a reminder.
Do not increase your dose or use this drug more often or for longer than prescribed. Your condition will not improve any faster, and your risk of side effects will increase.
It may take up to several months before you get the full benefit of this drug.
Tell your doctor if your condition does not get better or if it gets worse.