[In vitro studies on dosing interval of cefoperazone (author's transl)].

Serum pharmacokinetics of 1 g cefoperazone was simulated in vitro. Initial concentration was 190 microgram/ml, half-life 128 min. Bactericidal activity and regrowth interval was determined against 17 clinical isolates. Rapid initial killing was seen especially against E. coli, K. pneumoniae and E. cloacae and with some reservations also against P. aeruginosa. The bactericidal activity was slower against P. mirabilis and S. aureus. Only 8 out of 17 tested strains regrew to 1% mark between 8.5 and 12 h after exposure to cefoperazone was started. The regrowth interval ranged from 0.5 to 6.5 h.