Methotrexate (Rheumatrex, Trexall)
`
`Description
`Methotrexate (Rheumatrex) is one of the most effective and commonly used medicines in the treatment of
`several forms of arthritis and other rheumatic conditions. It is known as a disease-modifying anti-rheumatic
`drug (DMARD), because it not only decreases the pain and swelling of arthritis, but it also can decrease
`damage to joints and long-term disability.
`
`Fast Facts
`Methotrexate is one of the most commonly used drugs in the treatment of rheumatoid arthritis.
`It helps with pain and swelling and also slows the progression of arthritis over time.
`Methotrexate requires careful monitoring to reduce risk of liver injury and infections.
`Methotrexate can cause serious birth defects and should not be taken while pregnant or attempting to
`become pregnant or while breastfeeding.
`
`Uses
`Methotrexate has been used for decades to treat psoriasis and some cancers. It is used to treat rheumatoid
`arthritis and other forms of inflammatory arthritis and also may be used to treat lupus, inflammatory myositis,
`vasculitis, and some forms of childhood arthritis.
`
`How it works
`Methotrexate blocks several enzymes involved in the immune system. This affects actively growing cells such
`as those that are in the skin, blood, gastrointestinal tissues (i.e., stomach and intestines), and the immune
`system. However, it is not entirely clear how methotrexate decreases the severity of arthritis.
`
`Dosing
`Methotrexate typically comes in 2.5 milligram (mg) tablets. Adults with rheumatoid arthritis usually begin with
`a starting dose of 7.5 to 10 mg, or 3-4 pills, taken all together once a week. The dose may be increased to 20 to
`25 mg a week over time if needed. The medication also can be given as a liquid or as an injection. This comes
`as 25 mg per 1 milliliter (mL) and is injected under the skin, like insulin, to reduce side effects or when higher
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`doses are needed. Adults with other rheumatic conditions may take similar doses. In children with juvenile
`arthritis, the dose is based on the patient's weight.
`
`Time to effect
`Improvements in arthritis and other conditions usually are first seen in 3-6 weeks. The full benefit of this drug
`may not be seen until after 12 weeks of treatment.
`
`Side Effects
`The most common side effects of methotrexate include nausea or vomiting and abnormalities in liver function
`tests. Liver function tests are blood tests your doctor may order to watch your liver. These side effects are
`more likely to occur at higher doses. About 1-3 percent of patients develop mouth sores (called stomatitis),
`rash, diarrhea, and abnormalities in blood counts. Methotrexate may cause cirrhosis (scarring) of the liver, but
`this side effect is rare and most likely to occur in patients who already have liver problems or are taking other
`drugs that are toxic to the liver.
`
`Lung problems (persistent cough or unexplained shortness of breath) can occur when taking methotrexate.
`These side effects are more common in people with poor lung function. Persistent cough or shortness of
`breath should be reported to your doctor.
`
`Slow hair loss is seen in some patients, but hair grows back when the person stops taking this medication.
`Methotrexate can increase the sensitivity of the skin to sunlight, so limiting sun exposure and the use of
`sunscreen is advised.
`
`The use of folate supplements (folic and folinic acid) often are given with methotrexate. These are B vitamins
`and can decrease side effects during methotrexate treatment.
`
`It is important to remember that most patients do not experience side effects, and that, for those who do,
`many of the minor side effects will improve with time. Methotrexate treatment should be discontinued for at
`least three months before attempting to become pregnant. Even though methotrexate should not be taken
`during pregnancy, it does not reduce a woman’s chance of becoming pregnant in the future. Men taking
`methotrexate should talk to their physician prior to attempts to conceive.
`
`Points to remember
`Methotrexate should not be taken if you are pregnant or plan to become pregnant, or if kidney or liver
`function is not normal.
`
`It is important to take methotrexate exactly as directed. Generally, this medication should be taken on one day
`a week, but the dose is occasionally split into two doses all in one day per week to avoid side effects. Your
`doctor also may prescribe a folic acid (or folate) vitamin supplement to decrease the chance of side effects.
`Some side effects do not cause symptoms, so it is important to have routine blood tests performed every 8-12
`weeks.
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`If you miss a dose, you can generally take it up to 4-5 days later. If you do not realize that you missed a dose
`until the next dose is scheduled, talk to your doctor about what to do. If you are about to have surgery, talk to
`your doctor about whether or not to discontinue methotrexate. When methotrexate treatment is
`discontinued, its beneficial effects on arthritis symptoms gradually disappear over a period of 2-8 weeks.
`
`Alcohol significantly increases the risk for liver damage while taking methotrexate, so alcohol should be
`avoided while on this medication.
`
`Methotrexate can cause serious birth defects and complications during pregnancy, so it is important that
`you discuss birth control and pregnancy plans with your physician while taking this medication. An effective
`form of contraception is critical while taking methotrexate and for at least three months after stopping the
`medication. Some vaccinations should be avoided while taking this medication. Be sure to discuss with your
`doctor before receiving any vaccines. Also, be sure to notify your doctor before any surgeries while taking this
`medication.
`
`Drug interactions
`Be sure to tell your doctor about all of the medications you are taking, including over-the-counter drugs and
`natural remedies, as some of these could increase the risk of methotrexate toxicity. Trimethoprim (Bactrim or
`Septra), an antibiotic often used for respiratory and urinary infections, may increase the toxicity of
`methotrexate. The level of methotrexate can be affected by nonsteroidal anti-inflammatory drugs (NSAIDs),
`although these often are prescribed together for the management of rheumatoid arthritis. Other drugs that
`can affect the liver may increase the risk of liver damage from methotrexate. Radiation therapy, used to treat
`some cancers, may increase the risk of serious side effects from methotrexate as well.
`
`Information to Discuss with Your Primary Care Physician and other Specialists
`Be sure to tell your other physicians that you are taking this drug. Women taking this medication should
`discuss appropriate forms of birth control with their primary care physician or gynecologist. It is especially
`important that women discuss the use of this medicine (even past use) with their obstetrician/gynecologist.
`Live vaccines should be avoided while on this medication. You should discuss updating your vaccinations prior
`to starting this medication. Because this medication can lower your immunity, it is important that you discuss
`this with any physician treating you for an infection, as this may lead to a different evaluation or treatment.
`The risk of liver injury may be increased if methotrexate is combined with other medications. Be sure to
`discuss this with other physicians when new medications are prescribed.
`
`For more information
`The American College of Rheumatology has compiled this list to give you a starting point for your own
`additional research. The ACR does not endorse or maintain these Web sites, and is not responsible for any
`information or claims provided on them. It is always best to talk with your rheumatologist for more
`information and before making any decisions about your care.
`
`National Institutes of Health: Medline Plus Link
`www.nlm.nih.gov/medlineplus/druginfo/meds/a682019.html
`
`OTIS (Organization of Teratology Information Specialists) for information on methotrexate and pregnancy
`www.otispregnancy.org/files/methotrexate.pdf
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`Updated May 2012
`Written by Michael Cannon, MD, and reviewed by the American College of Rheumatology Communications and Marketing
`Committee.
`
`This patient fact sheet is provided for general education only. Individuals should consult a qualified health care provider for
`professional medical advice, diagnosis and treatment of a medical or health condition.
`
` ©
`
` 2012 American College of Rheumatology
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