Sulfonamides, also known as sulfa drugs, are a group of synthetic antibiotics that were first discovered in the 1930s. They work by inhibiting the growth of bacteria, specifically by interfering with the synthesis of folic acid, which is essential for bacterial reproduction. Sulfonamides are effective against a variety of bacterial infections and were among the first antibiotics used in medicine. These drugs are often used to treat conditions such as urinary tract infections and certain types of pneumonia. While their use has declined with the advent of more advanced antibiotics, sulfonamides remain important in specific cases, especially for patients who may be allergic to penicillin or other antibiotics.