Composition: Each tablet contains : Trimethoprim : ...........80 mg Sulfamethoxazole : ...400 mg Description: This combination is a fixed dose combination of Trimethoprim and sulfamethoxazole and is called cotrimoxazole. Trimethoprim is a diamino pyrimidine derivative which selectively inhibits bacterial dihydro folate reductase (DHFRase). It causes sequential block of folate metabolism and is 50,000 times more active against bacterial DHFRase thus human folate metabolism is not interfered at antibacterial concentration .Sulfamethoxazole has bacteriostatic activity as indvidual. It is very active against Pyogenic bacterial infections and is an intermediate acting sulfonamide. Sulfamethoxazole being a structural analogues of p-amino benzoic acid PABA, inhibit bacterial folate synthetase and hence folic acid synyhesis in bacteria suffers . Sulfamethoxazole and trimethoprim have nearly same T1/2(10 hours). It is used in thecombination of 5:1.This combination becomes bactericidal in the above mentioned Proportion. Primarily both sulfamethoxazole & trimehoprim are bacteriostatic but this combination becomes bactericidal even for those bacterias which are moderately resistant to any one of them.This combination has maximum synergism for organisms which are sensitive to both the components. Indications: * It is used for urinary tract infections. · For respiratory tract infections , typhoid, chronic bronchitis, facio- maxillary infections, otits media ,whooping cough . · Bacterial dirrohoeas and dysentery. · Chancroid , granuloma inguinale. · Septicaemias, gonorroea. · For prophylaxis & therapeutic treatment of severe infections. Contradications:Hypersensitivity to either of two. Not to be used in premature or infants of few weeks. Marked liver parenchymal damage, blood dyscarasis & seviour renal insufficiency & in patients with allergic history , urinary obstruction. Pediatrics: Not recommended. Pregnancy: Contradicated Lactation: Use with caution. Dosage: 1 or 2 tabs twice a day Presentation: Available as 25 ´ 10 tablets in a Multicarton.