Sulfacetamide is a synthetic sulfonamide antibiotic, which exerts its effect through inhibition of bacterial dihydrofolate synthetase, an enzyme responsible for the conversion of p-aminobenzoic acid into folic acid in bacterias. The topical formulation of the drug is prescribed for the treatment of acne vulgaris and the ophtalmic formulation is used in patients with eye infections.

Sulfadiazine is a sulfonamide antibiotic. The sulfonamides are synthetic bacteriostatic antibiotics with a wide spectrum against most gram-positive and many gram-negative organisms. However, many strains of an individual species may be resistant. Sulfonamides inhibit multiplication of bacteria by acting as competitive inhibitors of p-aminobenzoic acid in the folic acid metabolism cycle. Bacterial sensitivity is the same for the various sulfonamides, and resistance to one sulfonamide indicates resistance to all. Most sulfonamides are readily absorbed orally. However, parenteral administration is difficult, since the soluble sulfonamide salts are highly alkaline and irritating to the tissues. The sulfonamides are widely distributed throughout all tissues. High levels are achieved in pleural, peritoneal, synovial, and ocular fluids. Although these drugs are no longer used to treat meningitis, CSF levels are high in meningeal infections. Their antibacterial action is inhibited by pus. Sulfadiazine is a competitive inhibitor of the bacterial enzyme dihydropteroate synthetase. This enzyme is needed for the proper processing of para-aminobenzoic acid (PABA) which is essential for folic acid synthesis. The inhibited reaction is necessary in these organisms for the synthesis of folic acid. Used for the treatment of rheumatic fever and meningococcal meningitis.

Sodium sulfanilate is a salt of sulphanilic acid and has been used to monitor the degree of renal dysfunction in dogs.

Sulfamethazine is a sulfonamide used to treat a variety of bacterial diseases in animals. It inhibits bacterial synthesis of dihydrofolic acid by competing with para-aminobenzoic acid (PABA) for binding to dihydropteroate synthetase (dihydrofolate synthetase).

Sulfamerazine is a sulfonamide antibiotic, which acts by inhibiting folic acid synthesis in bacterias. The primary target of sulfamerazine is believed to be dihydropteroate synthetase. Sulfamerazine (in comination with Sulfadiazine and Sulfamethazine) was used in the US under different names, including the earliest brand of Neotrizine. Nowdays, the drugs containing sulfamerazine are no longer available for use in humans in the US, however, they may be prescribed for veterinary purposes.

Sulfaguanidine is used to treat the gastrointestinal infections particularly bacillary dysentery. Sulfaguanidine is a sulfonamide antibiotic that blocks the synthesis of dihydrofolic acid by inhibiting the enzyme dihydropteroate synthase in bacteria. Sulfonamides are active against Gram positive bacteria and Gram negative bacteria.

Sulfamethazine is a sulfonamide used to treat a variety of bacterial diseases in animals. It inhibits bacterial synthesis of dihydrofolic acid by competing with para-aminobenzoic acid (PABA) for binding to dihydropteroate synthetase (dihydrofolate synthetase).

Sulfamethazine is a sulfonamide used to treat a variety of bacterial diseases in animals. It inhibits bacterial synthesis of dihydrofolic acid by competing with para-aminobenzoic acid (PABA) for binding to dihydropteroate synthetase (dihydrofolate synthetase).

Sulfamethazine is a sulfonamide used to treat a variety of bacterial diseases in animals. It inhibits bacterial synthesis of dihydrofolic acid by competing with para-aminobenzoic acid (PABA) for binding to dihydropteroate synthetase (dihydrofolate synthetase).