<prompt> All of the following are topically used sulfonamides EXCEPT:SulfacetamideSulfasalazineSilver sulfadiazineMafenide  <response>: SULFONAMIDES: 1 . Sho acting 4-8 hr : Sulfadiazine 2. Intermediate acting 8-12 hr : Sulfamethm,azole 3. Long acting -7 days: Sulfadoxine, Sulfamethopyrazine 4. Special purpose sulfonamides: Sulfacetamide sod, Mafenide, Silver sulfadiazine, Sulfasalazine. Sulfasalazine Salicylazosulfapyridine It is a compound of 5-aminosalicylic acid 5-ASA with sulfapyridine linked through an azo bond that has a specific therapeutic effect in inflammatory bowel diseases IBDs like ulcerative colitis and Crohn;s disease.They are both locally and systemically acting agents. ESSENTIALS OF MEDICAL PHARMACOLOGY K.D.TRIPATHI SIXTH EDITION PAGE NO:661 