Azathioprine is a medication primarily used to suppress the immune system. It is often prescribed for conditions such as rheumatoid arthritis, inflammatory bowel disease, and to prevent organ rejection after transplants. By inhibiting the production of certain immune cells, it helps reduce inflammation and manage autoimmune responses. This drug is usually taken orally in tablet form, and its dosage may vary based on the condition being treated. Common side effects can include nausea, fatigue, and an increased risk of infections due to its immunosuppressive effects. Regular monitoring by a healthcare provider is essential while using Azathioprine.