Methotrexate Risks, Warnings, and Complications

MYELOSUPPRESSION AND INCREASED RISK OF INFECTIONS: Methotrexate can affect the bone marrow and result in a low number of blood cells. This can increase the risk of infections and bleeding. Inform your doctor if you have, or have ever had, low blood counts. Call your healthcare provider immediately if you develop fever, sore throat, chills, or other signs of active infection, abnormal bruising or bleeding, extreme fatigue, dyspnea, or pale skin. If you are taking treatment with methotrexate, your blood counts should be closely monitored regularly. Methotrexate can decrease the activity of the immune system and make the patients prone to serious opportunistic infections.

TOXICITY EFFECTS ON THE DIFFERENT BODY PARTS: Methotrexate may result in serious toxicity effects in different organs, i.e. gastrointestinal toxicity and renal toxicity. The drug can put stress on your lungs, liver, gastrointestinal system, kidneys, and nervous system and may lead to bone marrow suppression.

 The risk is higher in patients who are alcoholics, on higher doses, taking non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin, ibuprofen (Advil, Motrin), have impaired renal function, extra fluid in the stomach area or the space around your lungs. You may be more likely to experience severe methotrexate side effects if you have these conditions or take certain drugs. Your doctor will keep a closer eye on you and may need a dose reduction of methotrexate or maybe stop it completely. Call your doctor right away if you experience any of the following symptoms: Liver problems - yellowing of your skin or eyes, pain in the upper right side of your stomach or dark urine; Lung problems - cough, difficulty breathing; Kidney problems - swelling in feet or ankles or decreased or no urine; Stomach problems - nausea, vomiting, diarrhea; Skin problems - skin rash, high fever, sudden blisters; Nerve problems - vision changes, not able to move parts of your body, fatigue, confusion, and drowsiness

HARM OR DEATH OF UNBORN BABY: Methotrexate belongs to category X; thus, it is absolutely contraindicated for use in pregnancy. It can cause harm or death of the fetus. It is important to use a reliable method of birth control for both men and women. Pregnancy needs to be avoided for a minimum of 3 months in the case of men and 6 months in the case of women after the final dose. Talk to your doctor about other options if you or your partner are pregnant or plan to become pregnant.

ALLERGIC REACTIONS: Methotrexate can cause life-threatening allergic reactions. If you develop any of the following symptoms, tell your doctor immediately: fever, rash, blisters, hives, peeling skin, swellings on lips, face, throat, or swallowing difficulties. 

TUMOR LYSIS SYNDROME: Methotrexate can cause tumor lysis syndrome in patients with rapidly growing tumors. Inform your doctor immediately if you develop weakness, nausea, diarrhea, muscle cramps, tingling, or decreased urination. Your doctor can provide appropriate prophylactic medications prior to the start of methotrexate tablets in high-risk patients

INFERTILITY: Methotrexate might cause infertility issues in men (low sperm count) and women (menstrual problems), which might be irreversible. Hence, risks should be discussed with your doctor.

RISKS ASSOCIATED WITH LIVE VACCINES: Methotrexate may cause a weakened immune system. Thus, live vaccines such as chicken pox, measles, yellow fever, or mumps and rubella (MMR) vaccines should not be taken by patients. Inform your physician immediately if you experience sudden fever, muscle weakness, and speech or vision changes.

MEDICATION ERRORS: Since methotrexate is often only administered once per week, it is possible to mix up the dosage and inadvertently take more than one dose per week or forget to take it. Advise patients and health providers to take the correct dosage as indicated for patients on a once-weekly dosing schedule because medication errors have resulted in fatalities.

SECONDARY MALIGNANCIES: Using methotrexate may raise your likelihood of developing secondary cancers like lymphoma or acute lymphoblastic leukemia. If you develop lymphoma, it may go away on its own when you stop taking methotrexate, or it may require chemotherapy.

FOLIC ACID SUPPLEMENTATION: Methotrexate reduces folate levels in your body. The recommended dose of folic acid supplements is 5 mg taken orally once a week or 1 mg taken orally once a day, excluding the day you take methotrexate. It is crucial to avoid taking folic acid supplements on the same day as methotrexate.