Methotrexate is primarily used to treat which condition?

• A. Hypertension
• B. HIV infection
• C. Seizures
• D. Rheumatoid arthritis

Answer: (D)

Methotrexate acts as a disease-modifying antirheumatic drug used at low weekly doses to treat autoimmune arthritis, especially rheumatoid arthritis. It works by interrupting folate metabolism, which reduces the proliferation of rapidly dividing immune cells, and by increasing adenosine levels to dampen inflammation. This combination lowers joint inflammation, slows damage, and improves symptoms over time, making it the primary choice for RA among the options. It isn’t used for hypertension, HIV infection, or seizures, which are managed with antihypertensives, antiretrovirals, and anticonvulsants, respectively.