Methotrexates

Methotrexate is a synthetic antimetabolite drug primarily used in the treatment of certain types of cancer, autoimmune diseases, and ectopic pregnancy. It functions by inhibiting dihydrofolate reductase, an enzyme essential for DNA synthesis and repair, thereby slowing the growth of rapidly dividing cells such as cancer cells and overactive immune cells.

As an antineoplastic agent, methotrexate is commonly prescribed for acute lymphoblastic leukemia, choriocarcinoma, breast cancer, and non-Hodgkin lymphoma. In autoimmune conditions, it is frequently employed to manage severe psoriasis, rheumatoid arthritis, and inflammatory bowel disease by suppressing the immune response. For ectopic pregnancy, it may be used as an alternative to surgical intervention in specific cases.

The drug is typically administered orally, intramuscularly, or intravenously, with dosing varying depending on the condition being treated. High-dose methotrexate regimens often require leucovorin (folinic acid) rescue therapy to mitigate bone marrow suppression and toxicity. Common side effects include nausea, vomiting, mouth sores, and liver dysfunction, while long-term use may increase the risk of infections, lung fibrosis, and secondary malignancies.

Methotrexate interacts with several medications, including nonsteroidal anti-inflammatory drugs (NSAIDs), antibiotics, and other immunosuppressants, which can alter its efficacy or toxicity. Patients must avoid alcohol and maintain proper hydration while on treatment to reduce liver and kidney strain. Regular monitoring of blood counts, liver enzymes, and kidney function is essential during therapy.

Contraindications include pregnancy (due to teratogenic risks), severe renal or hepatic impairment, and hypersensitivity to the drug. Pregnant women and those planning conception should avoid methotrexate, as it can cause fetal abnormalities and miscarriage. Alternative treatments may be considered for individuals with a history of alcoholism or significant liver disease.