Methotrexate Side Effects

Methotrexate Side Effects

Methotrexate works by reducing the activity of the immune system and is useful for treating certain medical conditions such as rheumatoid arthritis. Here is a brief overview of the side effects of this drug.
Methotrexate is a drug used for treating certain types of cancer and autoimmune diseases. It is an antimetabolite and antifolate drug, and works by blocking the metabolism of folic acid. This drug acts specifically during DNA and RNA synthesis, and is cytotoxic during the S-phase of the cell cycle. It is commonly used in combination with misoprostol to terminate early pregnancies. It may also be used in case of a missed miscarriage, in which fetal demise has occurred, but the body has not expelled the fetus.

Methotrexate is used for treating various diseases like dermatomyositis, inclusion body myositis, ankylosing spondylitis, Crohn's disease, psoriasis, and rheumatoid arthritis. It is also used in the treatment of Beh├žet's disease, in which the medication is prescribed along with folic acid. In case of rheumatoid arthritis, methotrexate is given in a low dosage, in order to inhibit AICAR transformylase, which leads to an increased level of AICA ribose. The drug is useful for cancer chemotherapy, either singly or as a part of combination chemotherapy regimens. Methotrexate is still the mainstay of the treatment of many neoplastic disorders, such as acute lymphoblastic leukemia.

Adverse Effects

Nausea, Vomiting, and Diarrhea: Consumption of methotrexate can cause nausea and vomiting. However, these side effects can be reduced, if the drug is taken with food or in the evening. Anti-nausea tablets can be taken to reduce this side effect. Some patients may also develop diarrhea.

Ulcerative Stomatitis: This condition is characterized by small ulcers on the oral mucosa, covered by a grayish exudate. These small sores or painful swellings on the inside of the mouth, disappear on their own, usually within ten days, and they leave no scar. Ulcerative stomatitis is common in methotrexate users, but the condition vanishes within a short duration.

Infections Like Pneumonia: A patient on methotrexate may catch infections like pneumonia, sepsis, and nocardiosis. Besides these, there is also a risk of severe adverse reactions, if penicillin is prescribed along with this drug. When methotrexate is given via intrathecal (spinal) route, it may cause central nervous system reactions, such as headache, blurred vision, irritability, confusion, speech impairment, etc. Fortunately, these side effects occur rarely.

Skin Dryness: This is a common side effect, which may lead to skin rash and increased sensitivity to the sun. So, users are often advised to wear sunscreen and a hat, when they go out in the sun. Methotrexate can suppress hematopoiesis (formation of blood cells) and may cause anemia, pancytopenia, neutropenia, thrombocytopenia, and lymphoproliferative disorders.

Mild Tiredness and Headache: While on this drug, the patient may experience mild tiredness throughout the day. Headaches may occur frequently or infrequently. Besides these, other frequently reported adverse reactions include leukopenia, abdominal distress, sore throat, and pain while passing urine. Some patients develop muscle and joint pain, after taking their weekly dose.

Long-term use of methotrexate may cause liver problems. Those with poor lung function may develop lung problems too. Hair loss is another side effect that is seen in some of the users. Usually, doctors prescribe folic acid supplements to reduce the adverse effects of the drug. Methotrexate is not good for those with liver and kidney diseases, blood marrow or blood cell disorders, and lung diseases. In such cases, patients must inform their doctors beforehand. Although methotrexate is useful in the treatment of many diseases, the side effects should not be overlooked while one is on this medication. In case of any adverse reaction, seek immediate medical attention, to avoid complications.

Disclaimer: This article is for informational purposes only, and should not be used as a replacement for expert medical advice.