IN-VITRO ACTIVITY OF 2 NEW ORAL CEPHALOSPORINS, CEFIXIME AND CEFDINIR(CI-983), ON HUMAN PERIPHERAL MONONUCLEAR AND POLYMORPHONUCLEAR LEUKOCYTE FUNCTIONS

The in vitro effects of cefixime and cefdinir (CI 983), two so-called third-generation oral cephalosporin derivatives, on human polymorphonu clear and mononuclear phagocyte functions (random migration and chemot axis, specific and nonspecific phagocytosis, nitroblue tetrazolium red uction, superoxide production, microbicidal. activity) were studied. N either antibiotic, in the range of its attainable therapeutic concentr ation, exhibited any toxic effect on random migration, chemotaxis, met abolic activation and microbicidal mechanisms of phagocytic cells. Cef ixime did not interfere in phagocytosis while cefdinir enhanced both p hagocytosis frequency and index. The modulating effect on phagocytosis exerted by cefdinir was achieved at very low antibiotic concentration s (0.06 mg/l for polymorphonuclear leukocytes and 0.03 mg/l for monocy tes) when non-opsonized zymosan particles were used as phagocytic chal lenge. Moreover, the effect was demonstrated both in the presence of c efdinir and after pretreatment of cells with the antibiotic and its re moval by washings. As for specific phagocytosis, parameters were sligh tly increased by cefdinir but only the phagocytosis index was signific antly improved in the presence of 2 mg/l of antibiotic.