Cyclosporine is an immunosuppressive medication primarily used to prevent organ rejection in transplant patients. It works by inhibiting the activity of certain immune cells, thereby reducing the body's immune response. This helps to ensure that the transplanted organ is accepted and functions properly. In addition to its use in transplants, Cyclosporine is also prescribed for autoimmune conditions like rheumatoid arthritis and psoriasis. It is available in various forms, including capsules and oral solutions, and requires careful monitoring due to potential side effects, such as kidney damage and increased risk of infections.