Which condition is a contraindication for methotrexate use?

Methotrexate is a medication that is commonly used in oncology for the treatment of various cancers, as well as in rheumatology for autoimmune diseases. It works as an antimetabolite, interfering with the DNA synthesis of rapidly dividing cells. However, its use is fraught with significant risks, particularly in vulnerable populations such as pregnant individuals.

Pregnancy is a critical contraindication for methotrexate use because it poses severe risks to the developing fetus, including congenital malformations, miscarriage, and ectopic pregnancy. Methotrexate is known to be teratogenic, meaning it can cause birth defects if administered during pregnancy. Healthcare providers always advise that women of childbearing age either avoid pregnancy or use effective contraception while undergoing treatment with methotrexate.

While allergic reactions to the drug itself can also contraindicate its use, this is generally assessed on an individual basis rather than being a blanket contraindication like pregnancy. High blood pressure and certain skin conditions, though they may require caution, do not categorically prevent the use of methotrexate in the same way that pregnancy does. Thus, pregnancy stands out as a significant and well-established contraindication for the use of methotrexate.