Methotrexate

pronounced as (meth'' oh trex' ate)

Brand Name(s): Rheumatrex®, Trexall®, also available generically

Why is this medicine prescribed?

Methotrexate is used to treat severe psoriasis (a skin disease in which red, scaly patches form on some areas of the body) that cannot be controlled by other treatments. Methotrexate is also used along with rest, physical therapy, and sometimes other medications to treat severe active rheumatoid arthritis (RA; a condition in which the body attacks its own joints, causing pain, swelling, and loss of function) that cannot be controlled by certain other medications. Methotrexate is also used to treat certain types of cancer including cancers that begin in the tissues that form around a fertilized egg in the uterus, breast cancer, lung cancer, certain cancers of the head and neck, certain types of lymphoma, and leukemia (cancer that begins in the white blood cells). Methotrexate is in a class of medications called antimetabolites. Methotrexate treats cancer by slowing the growth of cancer cells. Methotrexate treats psoriasis by slowing the growth of skin cells to stop scales from forming. Methotrexate may treat rheumatoid arthritis by decreasing the activity of the immune system.

Are there other uses for this medicine?

Methotrexate is also sometimes used to treat Crohn's disease (condition in which the immune system attacks the lining of the digestive tract, causing pain, diarrhea, weight loss and fever), multiple sclerosis (MS; condition in which the immune system attacks the nerves, causing weakness, numbness, loss of muscle coordination, and problems with vision, speech, and bladder control), and other autoimmune diseases (conditions that develop when the immune system attacks healthy cells in the body by mistake). Ask your doctor about the risks of using this medication for your condition.

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

How should this medicine be used?

Methotrexate comes as a tablet to take by mouth. Your doctor will tell you how often you should take methotrexate. The schedule depends on the condition you have and on how your body responds to the medication.

Your doctor may tell you to take methotrexate on a rotating schedule that alternates several days when you take methotrexate with several days or weeks when you do not take the medication. Follow these directions carefully and ask your doctor or pharmacist if you do not know when to take your medication.

If you are taking methotrexate to treat psoriasis or rheumatoid arthritis, your doctor may tell you to take the medication once a week. Pay close attention to your doctor's directions. Some people who mistakenly took methotrexate once daily instead of once weekly experienced very severe side effects or died.

Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take methotrexate exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

If you are taking methotrexate to treat psoriasis or rheumatoid arthritis, your doctor may start you on a low dose of the medication and gradually increase your dose. Follow these directions carefully.

If you are taking methotrexate to treat rheumatoid arthritis, it may take 3 to 6 weeks for your symptoms to begin to improve, and 12 weeks or longer for you to feel the full benefit of methotrexate. Continue to take methotrexate even if you feel well. Do not stop taking methotrexate without talking to your doctor.

What special precautions should I follow?

Before taking methotrexate,

  • tell your doctor and pharmacist if you are allergic to methotrexate, any other medications, or any of the ingredients in methotrexate tablets. Ask your doctor or pharmacist for a list of the ingredients.
  • tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention the medications listed in the IMPORTANT WARNING section and any of the following: certain antibiotics such as chloramphenicol (chloromycetin), penicillins, and tetracyclines; folic acid (available alone or as an ingredient in some multivitamins); other medications for rheumatoid arthritis; phenytoin (Dilantin); probenecid (Benemid); sulfonamides such as co-trimoxazole (Bactrim, Septra), sulfadiazine, sulfamethizole (Urobiotic), and sulfisoxazole (Gantrisin); and theophylline (Theochron, Theolair). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
  • tell your doctor if you have or have ever had any of the conditions mentioned in the IMPORTANT WARNING section or a low level of folate in your blood.
  • do not breast-feed while you are taking methotrexate.
  • plan to avoid unnecessary or prolonged exposure to sunlight or ultraviolet light (tanning beds and sunlamps) and to wear protective clothing, sunglasses, and sunscreen. Methotrexate may make your skin sensitive to sunlight or ultraviolet light. If you have psoriasis, your sores may get worse if you expose your skin to sunlight while you are taking methotrexate.
  • do not have any vaccinations during your treatment with methotrexate without talking to your doctor.
  • if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking methotrexate.

What special dietary instructions should I follow?

Unless your doctor tells you otherwise, continue your normal diet.

What should I do if I forget to take a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

What should I do in case of overdose?

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help . If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

What side effects can this medicine cause?

Methotrexate may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • dizziness
  • drowsiness
  • headache
  • swollen, tender gums
  • decreased appetite
  • reddened eyes
  • hair loss

Some side effects can be serious. If you experience any of these symptoms or those listed in the IMPORTANT WARNING section, call your doctor immediately:

  • blurred vision or sudden loss of vision
  • seizures
  • confusion
  • weakness or difficulty moving one or both sides of the body
  • loss of consciousness

Methotrexate may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online ( http://www.fda.gov/Safety/MedWatch ) or by phone (1-800-332-1088).

What should I know about storage and disposal of this medication?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website ( http://goo.gl/c4Rm4p ) for more information if you do not have access to a take-back program.

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

What other information should I know?

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

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