SREE CHITHRA TIRUNAL INSTITUTE FOR MEDICAL SCIENCES TECHNOLOGY

species, hemophilus, streptococcus bovisand viridans. 1t acts by inhibiting 50S ribosomesub units and interferes with translocation( 19-23).Following a single oral dose of 500mg, Azt is eliminated from serum in apolyphasic manner.Initial rapid decline in the plasma level is due to the tissuedistribution and late by distribution and elimination.Terminal elimination phase ischaracterized by movement of Azt from the tissue compar1ments into the vascularcompartment, elimination by I iver and trans intestinal passage. Terminal serum hal f-1 i fewith a 500mg single oral dose is more than 40 hours.20.Baldwin et al in u trialconducted in UK measured pulmonary tissue concentration of Azt after a single oral doseof 500mg. Concentration of Azt achieved in sputum (mean peak 1.56mg/L), bronchialIIJucosa (mean peak 3.89mg/L) and alveolar macrophages (mean peak 23mg/L) wereHustained for 4 days well above an MIC of most respiratory pathogens includingstreptococci. Predominant portion of absorbed Azt remains un metabolized in the body.When metabolism occurs, it is primarily by de methylation. Metabolites have no antimicrobial activity. 20. This long effect makes it an ideal agent suitable for widely spacedintervals of administration.