[Pharmacokinetics and tissue distribution of azithromycin in humans]

Azithromycin(AZM) is a new macrolides antibiotic developed by Pfizer Inc. of the US. It has a 15-membered ring structure obtainable by introducing methyl-substituted nitrogen into a 14-membered ring lactone of erythromycin(EM). An effective drug concentration is sustained long owning to its superiority in tissue distribution and long half life(T1/2). AZM is also demonstrated to be twice to three times more powerful than the existing macrolides owning to its reinforced antimicrobial activity against Gram-negative microorganisms including influenza virus. AZM is already used in clinical practice in foreign countries and its excellent clinical performance has been demonstrated by the data. As for the domestic basic and clinical studies of AZM, Phase I study was initiated in 1991 following completion of nonclinical studies, and general clinical studies, a dose-setting study and Phase III controlled studies were conducted between 1992 and 1994. Usefulness of AZM is substantiated by the data from those studies.