methotrexate (meth oh TREX ayt)
Rheumatrex (2.5 mg, Vials for injection )
This drug is available in a generic form.
What is methotrexate?
This is a chemotherapy drug initially used to treat certain forms of leukemia. It has an effect on the bone marrow cells and other actively dividing cells in the body. It also has an effect on the immune system so that in certain disorders where the immune system is overactive, such as rheumatoid arthritis, psoriasis and inflammatory bowel disease, it has found a role. This is a potent drug and should not be used unless there is full understanding by the patient and close follow up by the physician.
What is it used for?
This drug is used in certain forms of leukemia, rheumatoid arthritis and severe psoriasis. In the field of gastroenterology it may be effective in treating inflammatory bowel disease, especially Crohn’s disease.
How do I take it?
Follow your physician’s instructions carefully. It is very important that you completely understand how to take this drug. In gastroenterology, the drug is usually given by injection only once a week. When tablets are taken, it is usually once a week or the dose is divided into 3 separate parts, taken 12 hours apart, again once a week. Methotrexate may be taken with food or milk to reduce stomach irritation. If nausea or vomiting develops, try eating dry foods (toast, crackers) or soups or unsweetened juices in several small meals throughout the day. It is recommended that 2 to 3 quarts of liquid be ingested every day to maintain good urine flow. Tablets may be crushed for ease in swallowing. Store at room temperature in tightly sealed container. Keep all medications away from children. Never share your medications with anyone else.
What do I do for a missed dose?
This drug is potent and its proper administration is important enough that a missed dose should be very unusual. If you remember a missed dose within 24 hours, it is usually satisfactory to resume your regular schedule. You should discuss missed doses with your physician.
Are there interactions with food or beverages?
There are no known interactions with foods with the tablet form of therapy. Highly seasoned foods may increase the chances of stomach irritation. This medication may be taken with milk. Avoid alcohol completely as methotrexate and alcohol can cause irreversible damage to the liver leading to cirrhosis.
An interaction generally means that one drug may increase or decrease the effect of another drug. Also, the more medications a person takes, the more likely there will be a drug interaction.
Interactions with this drug may occur with the following:
- digoxin (Lanoxin)
- phenytoin (Dilantin)
- aspirin or other salicylates
- arthritis drugs (ibuprofen, Advil, Motrin, Naprosyn, Voltaren, Lodine)
- bismuth subsalicylate (Pepto Bismol)
- carbenicillin (Geocillin)
- cholestyramine (Questran)
- sulfa drugs (Bactrim)
- cyclosporine (Sandimmune, Neoral)
- etretinate (Tegison)
- thiazide diuretics (Dyazide, hydrochlorothiazide)
- blood thinners (Coumadin)
- azathioprine (Imuran)
Is there a problem if I have another disorder or disease?
At times, a drug may have a different or enhanced effect when other diseases are present. At other times, the drug may worsen or effect another disease.
With this drug, the following disorders may be a problem:
- chronic liver disease or cirrhosis
- recurrent infections
- chronic neurologic disease
- chronic lung disease or fibrosis
- chronic kidney disease
What about allergies?
People who have known allergies or asthma may be at an increased risk for a reaction from any new medication. The physician should always know a patient’s allergy history. Signs of an allergic reaction are skin rash, hives and itching. Of course, a person should not take methotrexate if there has been a previous reaction to this or other chemotherapy drugs.
What if I’m pregnant, considering pregnancy or breast-feeding?
Most females now know that, if possible, no drug, including alcohol, should be taken during pregnancy or lactation. The potential danger, of course, is an injury to the baby. However, some drugs are much safer than others in this regard. So, the FDA has a grading system for each drug which reflects what is known medically. It ranks drugs from A, where medical studies show no evidence for danger to the fetus or mother, to B, C, D and X, where the medical evidence indicates that the risk to the fetus outweighs any benefit to the mother. Methotrexate is ranked X. Do not use methotrexate if you are pregnant or planning a pregnancy because of its significant risk of birth defects or miscarriage. Contraception should be used for the duration of therapy. Methotrexate is present in breast milk, so avoid methotrexate or stop nursing throughout therapy. After therapy males should wait at least 3 months and a woman should wait for the completion of at least one menstrual cycle before attempting to conceive. Always consult your physician before taking any drug during or when planning pregnancy.
What are the effects on sexual function?
In females, methotrexate can alter the menstrual cycle. In males, it can cause swelling or tenderness of the breasts. It can also lower the sperm count.
Are there other precautions?
Because this drug suppresses the body’s immune system, vaccination with a live virus vaccine should be avoided for the duration of the therapy. It is possible for the live virus vaccine to actually produce an infection rather than stimulate an immune response. Also, inform your physician of recent exposure to chicken pox or shingles. Methotrexate may cause drowsiness or dizziness so avoid driving or operating hazardous machinery until the full effect of the drug has been determined. This drug can also cause photosensitivity so limit sun exposure until your skin sensitivity is known.
How long is it safe to take methotrexate?
The use of methotrexate on a regular basis for several weeks is required to determine its effectiveness. Long-term use of months to years requires regular physician supervision.
How about side effects?
Adverse reactions can occur with any drug, even over-the-counter medications. Some of these are mild such as a stomach upset, which may be avoided by taking the medication with food. Minor reactions may go away on their own but if they persist, contact the physician. For major reactions, the patient should contact the physician immediately.
For methotrexate, the following are the observed side effects:
- sore mouth
- loss of hair
- sore throat
- abnormal bleeding or bruising
- difficult breathing
- stomach pain
- bloody stools
- yellow color to skin or eyes
A physician’s comment…
This potent drug is generally used in gastroenterology only when other forms of treatment have been ineffective. The drug is usually given once a week. Very careful blood testing is necessary to be sure the proper dose is being given. In the future, newer drugs for Crohn’s disease, may make it unnecessary to use methotrexate.