Sulfonamide research led to the discovery of dapsone and sulfasalzine. Both of these latter drugs have found a niche in the dermatological armamentarium especially for treatment of numerous non-infectious, inflammatory, autoimmune, and bullous disesases. These drugs, however, have side effects which include toxic hepatitis, neuropathy, cholestatic jaundice, hemolysis and methemoglobinemia. In the case of sulfasalamine, it is a conjugate of mesalamine and sulfapyridine. Of note, the latter moiety, sulfapyridine, is no longer available for human use as a separate drug due to side effects. In regards again with sulfasalazine, a pharmacology textbook credits mesalamine to be the major therapeutic moiety, while sulfapyridine is the culprit of the most significant adverse effects.