---Salazopyrin is used to treat ulcerative colitis, rheumatoid arthritis, and rheumatoid arthritis in adults. Salazopyrin contains sulfasalazine, which is classified as a disease-modifying anti-inflammatory drug (DMARD). Salazopyrin works by reducing inflammation in the body, especially parts of the body and the immune system. Salazopyrin helps reduce pain and improve symptoms of conditions such as rheumatoid arthritis and other diseases of the immune system.