The original antibacterial sulfonamides are synthetic (nonantibiotic) antimicrobial agents that contain the sulfonamide group. Sulfamethoxazole is contraindicated in people with a known hypersensitivity to trimethoprim or sulfonamides. Many drugs contain sulfur; early examples being antibacterial sulfonamides, known as "sulfa drugs". This was later followed by sulfonamides (sulfa drugs) and penicillin. Treatment is done by using antibiotics such as erythromycin, dihydrostreptomycin, streptomycin, sulfonamides, tylosin, and fluoroquinolones. Sulfonamides (sulfadiazine or sulfamethoxazole) may be added for treatment of neurological symptoms. Tertiary aromatic amines, hydrazines, hydroxylamines, sulfonamides, and indoles have all been reported. The sulfonylureas and thiazide diuretics are newer drug groups based upon the antibacterial sulfonamides. Some sulfonamides are also devoid of antibacterial activity, e.g., the anticonvulsant sultiame. It also excluded synthetic antibacterial compounds such as the sulfonamides. Some of the most effective DMGs are amides, carbamates, sulfones and sulfonamides. It was later largely superseded by penicillin and other sulfonamides. Similarly, with sulfonyl chlorides, one obtains sulfonamides. Those allergic to sulfonamides may be allergic to dorzolamide. DHPS is the target of sulfonamides, which are substrate analogues that compete with para-aminobenzoic acid.