Oral bactericid

A It U. Ac II NO, Fnhcplin, Control of black head in turkeys oral bactericids also named Nitasol 26.37R. 1619... 

Although tyrothricia is too toxic for parenteral therapy, it was formerly sold in the United States as oral lo2enges. Modem tyrothricin formulations are composed of 70—80% tyrocidines and 30—20% linear gramicidins. Tyrocidines are not as active as linear gramicidins and are too toxic for any therapeutic use by themselves. The bactericidal linear gramicidins are used in the United States solely as an ophthalmic solution in combination with polymyxin B sulfate and neomycin sulfate. The linear gramicidin is used in this aqueous product as a substitute for bacitracin, which lacks stabiUty under such conditions. 

While it may be desirable to limit the excess, chronic and inappropriate generation of phagocyte-derived ROMs, it is necessary to achieve this without simultaneously compromising their vital bactericidal function. The orally effective iron chelator 2,3-dihydroxybenzoate has been shown to decrease PMN ROM generation without a corresponding loss of bactericidal activity to phagocytosed Staphylococctis aureus (Boxer et al., 1978). 

Rifampin inhibits the bacterial enzyme that catalyzes DNA template-directed RNA transcription, i.e DNA-de-pendent RNA polymerase. Rifampin acts bactericidally against mycobacteria (M. tuberculosis, M. leprae), as well as many gram-positive and gram-negative bacteria It is well absorbed after oral ingestion. Because resistance may develop with frequent usage, it is restricted to the treatment of tuberculosis and leprosy (p. 280). 

Isoniazid is bactericidal against growing M. tuberculosis. Its mechanism of action remains unclear. (In the bacterium it is converted to isonicotinic acid, which is membrane impermeable, hence likely to accumulate intracellu-larly.) Isoniazid is rapidly absorbed after oral administration. In the liver, it is inactivated by acetylation, the rate of which is genetically controlled and shows a characteristic distribution in different ethnic groups (fast vs. slow acetylators). Notable adverse effects are peripheral neuropathy, optic neuritis preventable by administration of vitamin Be (pyridoxine) hepatitis, jaundice. 

Pyrazinamide exerts a bactericidal action by an unknown mechanism. It is given orally. Pyrazinamide may impair liver function hyperuricemia results from inhibition of renal urate elimination. 

Dapsone is a sulfone that, like sulfonamides, inhibits dihydrofolate synthesis (p. 272). It is bactericidal against susceptible strains of M. leprae. Dapsone is given orally. The most frequent adverse effect is methemoglobinemia with accelerated erythrocyte degradation (hemolysis). 

Clofazimine is a dye with bactericidal activity against M. leprae and antiinflammatory properties. It is given orally, but is incompletely absorbed. Because of its high lipophilicity, it accumulates in adipose and other tissues and leaves the body only rather slowly (ti/2 - 70 d). Red-brown skin pigmentation is an unwanted effect, particularly in fair-skinned patients. 

Clofazimine is a weakly bactericidal dye that has some activity against M. leprae. Its precise mechanism of action is unknown but may involve mycobacterial DNA binding. Its oral absorption is quite variable, with 9 to 70% of the drug eliminated in the feces. Clofazimine achieves significant concentrations in tissues, including the phagocytic cells it has a plasma half-life of 70 days. It is primarily excreted in bile, with less than 1% excretion in urine. 

Several experiments have shown the bactericidal effect of fluoride ions at high concentrations [180,181]. This effect generally occurs at concentrations well above those generally observed in saliva however, the use of fluoridated toothpaste or dental topical applications of fluoride may temporarily elevate the fluoride concentration in the oral cavity to bactericidal levels. It has been demonstrated that fluoride affects the metabolism of oral bacteria and reduces its acid tolerance. It is most effective at acidic pH values and, for example, fluoride levels as low as 0.1 mM can cause the complete arrest of glycolysis by Steptococcus mutans. It has been suggested that modifying the biological fluids related to the presence... 

Cefixime is an orally active third-generation cephalosporin antibiotic which has marked in-vitro bactericidal activity against a wide variety of gram positive and negative organisms. It is indicated for the treatment of urinary tract, infection, respiratory tract infection and biliary tract infection etc. 

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