Bactericidal effect of cefodizime against beta-lactamase-producing Neisseria gonorrhoeae in vitro. A comparison of level profiles in serum and tissue after intramuscular and intravenous administration in man.

Serum and skin suction blister fluid (SBF) level profiles as well as the profile in the hypothetical peripheral compartment in man after the single intravenous application of 1 g of cefodizime and the corresponding serum level profile after intramuscular application were simulated in the presence of beta-lactamase-producing gonococci. A rapid reduction of bacterial density was observed under each of these conditions indicating clinical efficacy of both treatment protocols in uncomplicated gonorrhoea. Considering the different level profiles in more detail both serum level profiles after intravenous and intramuscular injection turned out similarly effective: while the time needed for a 99% reduction of gonococcal density (t99%) was slightly shorter with the intravenous profile (1.45 vs. 1.68 h), the maximum relative reduction was somewhat smaller, expressed by a higher kn value (0.00024 vs. 0.00010%). The drug level profile in the hypothetical peripheral compartment proved on the whole equally effective as the serum level profiles. The suction blister fluid level profile, however, showed an inferior antigonococcal activity (kn = 0.00076%, t99% = 2.08 h). This demonstrates the value of the determination of SBF levels and their inclusion in in-vitro simulation experiments.