Methotrexate is a chemotherapy and immunosuppressive drug. It belongs to a group called antimetabolites (folic acid antagonists). It can be used in cancer treatment, autoimmune diseases, and some other medical conditions.

Mechanism
Methotrexate blocks an enzyme called dihydrofolate reductase (DHFR). This enzyme is needed to make DNA and RNA. By blocking it, Methotrexate prevents cells (especially fast-growing cells like cancer cells and overactive immune cells) from dividing and multiplying.

Uses

• Cancers: leukemia, lymphoma, breast cancer, head & neck cancers, osteosarcoma, etc.

• Autoimmune diseases: rheumatoid arthritis, psoriasis, Crohn’s disease.

• Ectopic pregnancy: to stop the growth of pregnancy outside the uterus.

  Adverse Effects
  Common side effects:

  • Nausea, vomiting, diarrhea

  • Mouth sores

  • Tiredness, weakness

  • Loss of appetite

  • Hair thinning