sulfonamide /səlfon″əmīd/ , originally one of a large group of synthetic bacteriostatic drugs that are effective in treating infections caused by many gram-negative and gram-positive microorganisms. They are bacteriostatic rather than bactericidal. Some sulfonamides are short-acting, some are intermediate-acting, and some are long-acting, depending on the speed with which they are excreted. They are used in treating many urinary tract infections. A variety of other types of drugs have since been developed that are sulfonamide derivatives, including thiazide diuretics and some of the oral hypoglycemics. Some people are hypersensitive to the sulfonamides. Sulfonamides are given with caution to people who have impaired liver or kidney function, and they are not given in the last trimester of pregnancy or to young infants, because cognitive impairment sometimes can result. Hemolytic anemia; agranulocytosis; thrombocytopenia; or aplastic anemia, drug fever, and jaundice may occur, particularly with long-acting sulfonamides given for more than 10 days. Most sulfonamides are given orally.
