For the treatment bacterial infections causing bronchitis, prostatitis and urinary tract infections.
Sulfamethazine is a sulfonamide drug that inhibits bacterial synthesis of dihydrofolic acid by competing with para-aminobenzoic acid (PABA) for binding to dihydropteroate synthetase (dihydrofolate synthetase). Sulfamethazine is bacteriostatic in nature. Inhibition of dihydrofolic acid synthesis decreases the synthesis of bacterial nucleotides and DNA.
Mechanism of action
Sulfonamides inhibit the enzymatic conversion of pteridine and p-aminobenzoic acid (PABA) to dihydropteroic acid by competing with PABA for binding to dihydrofolate synthetase, an intermediate of tetrahydrofolic acid (THF) synthesis. THF is required for the synthesis of purines and dTMP and inhibition of its synthesis inhibits bacterial growth. Pyrimethamine and trimethoprim inhibit dihydrofolate reductase, another step in THF synthesis, and therefore act synergistically with the sulfonamides.
Sulfamethazine may cause nausea, vomiting, diarrhea and hypersensitivity reactions. Hematologic effects such as anemia, agranulocytosis, thrombocytopenia and hemolytic anemia in patients with glucose-6-phosphate dehydrogenase deficiency may also occur. Sulfamethoxazole may displace bilirubin from albumin binding sites causing jaundice or kernicterus in newborns.
This compound belongs to the class of chemical entities known as aminobenzenesulfonamides. These are organic compounds containing a benzenesulfonamide moiety with an amine group attached to the benzene ring.
Hong YL, Hossler PA, Calhoun DH, Meshnick SR: Inhibition of recombinant Pneumocystis carinii dihydropteroate synthetase by sulfa drugs. Antimicrob Agents Chemother. 1995 Aug;39(8):1756-63. [PubMed:7486915 ]
Friaza V, Morilla R, Respaldiza N, de la Horra C, Calderon EJ: Pneumocystis jiroveci dihydropteroate synthase gene mutations among colonized individuals and Pneumocystis pneumonia patients from Spain. Postgrad Med. 2010 Nov;122(6):24-8. doi: 10.3810/pgm.2010.11.2219. [PubMed:21084778 ]
Thijssen HH: A simplified radioassay method of dihydropteroate synthetase activity in Escherichia coli and its application for an inhibition study of p-aminobenzoi acid derivatives. Anal Biochem. 1973 Jun;53(2):579-85. [PubMed:4577373 ]
Catalyzes the transfer of the acetyl group from acetyl coenzyme A to the free amino group of arylamines and hydrazines (PubMed:18795795). Is able to utilize not only acetyl-CoA, but also n-propionyl-CoA and acetoacetyl-CoA as acyl donors, although at a lower rate (PubMed:19014350). As acetyl-CoA and propionyl-CoA are products of cholesterol catabolism and the nat gene is likely present in the same operon than genes involved in cholesterol degradation, this enzyme could have a role in the utilization and regulation of these CoA species (PubMed:19014350).
Serum albumin, the main protein of plasma, has a good binding capacity for water, Ca(2+), Na(+), K(+), fatty acids, hormones, bilirubin and drugs. Its main function is the regulation of the colloidal osmotic pressure of blood. Major zinc transporter in plasma, typically binds about 80% of all plasma zinc.
Bratlid D, Bergan T: Displacement of albumin-bound antimicrobial agents by bilirubin. Pharmacology. 1976;14(5):464-72. [PubMed:1031216 ]
Angelakou A, Valsami G, Koupparis M, Macheras P: Use of 1-anilino-8-napthalenesulphonate as an ion probe for the potentiometric study of the binding of sulphonamides to bovine serum albumin and plasma. J Pharm Pharmacol. 1993 May;45(5):434-8. [PubMed:8099962 ]
Drug created on August 29, 2007 08:54 / Updated on July 18, 2017 17:00