👉 Immunosuppressants are medications used to treat or prevent the immune system from attacking healthy cells, such as cancerous ones. These drugs work by blocking the body's ability to produce certain types of white blood cells called T-cells, which play a critical role in fighting infections and diseases. The main classes of immunosuppressant drugs include: 1. Corticosteroids: Used to treat conditions like rheumatoid arthritis, psoriatic arthritis, and lupus. 2