Which drug is considered both an immunosuppressant agent and a DMARD?

Methotrexate is considered both an immunosuppressant and a disease-modifying antirheumatic drug (DMARD) due to its ability to inhibit cellular proliferation and modulate the immune response. It is commonly used in the treatment of conditions such as rheumatoid arthritis and certain cancers.

As an immunosuppressant, methotrexate works by interfering with the metabolism of folate, which is essential for the synthesis of DNA and RNA. This action reduces the activity of immune cells, ultimately leading to decreased inflammation and disease activity. In the context of rheumatoid arthritis and other autoimmune diseases, this immunosuppressive effect helps manage symptoms and slows disease progression.

As a DMARD specifically, methotrexate has been shown to modify disease outcomes by reducing radiographic progression and helping preserve joint function over time. It is a foundational treatment in rheumatology due to its efficacy and safety profile.

Other drugs in the options serve different roles or mechanisms. While azathioprine is also an immunosuppressant, it does not have the same established role as a DMARD for conditions like rheumatoid arthritis. Hydroxychloroquine is primarily an antimalarial that is used in rheumatoid arthritis but is not classified as a DMARD in the same