Rheumatrex 2.5 mg, containing Methotrexate Sodium, is widely used for various serious conditions such as psoriasis, rheumatoid arthritis, leukemia, lymphoma, breast cancer, and lung cancer. Known by other names like Abitrexate, Folex, Mexate, Trexall, and Fleotrexate, this medication works by inhibiting cell growth, which is crucial in both autoimmune diseases and cancer treatment. For autoimmune conditions, Methotrexate modulates the immune system, reducing inflammation and disease activity. In oncology, it targets rapidly dividing cells, helping to control cancer progression. Side effects can include nausea, fatigue, mouth sores, and potential liver toxicity, making regular monitoring essential. Rheumatrex's versatility in treating a range of severe conditions underscores its importance in both rheumatology and oncology, providing significant therapeutic benefits across multiple diseases.