[Azithromycin, pharmacodynamic evaluation in animal models].

Several experimental models have been used in order to evaluate the in vivo efficacy of azithromycin against numerous human pathogenic bacteria and parasites, including comparison between azithromycin and other antibiotics belonging or not to the macrolide family. Using the experimental models, three major objectives can be distinguished: the comparative studies of the efficacy dose 50 (ED50) of azithromycin compared to other orally given antibiotics, the azithromycin efficacy in animal infected with intracellular multiplying micro-organisms, and the demonstration of the specific azithromycin accumulation in tissues in direct relationship with the local recruitment of phagocytic cells at the infectious foci. The ED50 of azithromycin has been compared with those of erythromycin or cefaclor in varying acute murine infections. Evidence was given of a similar efficacy for the three tested antibiotics. Nevertheless a marked advantage for azithromycin was observed in experimental local infections and with infections due to Gram-negative bacteria (Haemophilus influenzae, Branhamella catarrhalis). The second objective was to confirm in vivo the preferential efficacy of azithromycin in models using intracellular multiplying microorganisms, due to its great capacity to accumulate inside of professional phagocytes. Several models have been used, such as those performed with Listeria monocytogenes, Legionella pneumophila, S. typhimurium, Brucella melitensis, M. avium and C. trachomatis.(ABSTRACT TRUNCATED AT 250 WORDS)