[Antibacterial activity of ciprofloxacin in the urine during four days after a single 500 mg and 750 mg oral dose].

Antibacterial activity of ciprofloxacin was studied in the urine after a single 500 mg and 750 mg oral dose in ten healthy female volunteers. Urine was collected, after each single oral dose, during seven time periods: 0-3 h, 3-6 h, 6-12 h, 12-24 h, 24-48 h, 48-72 h, 72-96 h. Ciprofloxacin concentrations were assayed by microbiological method. Urine antibacterial activity was determined for five bacterial strains isolated in urine: 2 E. coli strains, one sensitive and the other resistant to nalidixic acid (Nal-A), 1 Klebsiella pneumoniae resistant to nalidixic acid (Nal-B), 1 Staphylococcus saprophyticus and 1 Enterococcus faecalis. MICs of ciprofloxacin against these strains were respectively 0.003, 0.06, 0.25, 0.06 and 0.5 micrograms/ml. Ciprofloxacin mean concentrations in the seven urine samples were 292.5 +/- 55.8, 81.1 +/- 16.9, 43.7 +/- 11.6, 11.5 +/- 1.9, 1.3 +/- 0.2, 0.3 +/- 0.05 et 0.1 +/- 0.05 micrograms/ml after a single 500 mg oral dose and 215.1 +/- 68.1, 56.1 +/- 17.8, 43 +/- 8.8, 14.4 +/- 5.5, 1.4 +/- 0.2, 0.4 +/- 0.1 and 0.2 +/- 0.05 micrograms/ml after a single 750 mg oral dose. Urine bacteriostatic activity was not very different after a 500 mg dose and a 750 mg dose. Against enterobacteriacae, after a 500 mg dose it was > or = 16 the first day; it was > or = 512 for the Nal-S E. coli. It was > or = 64 the first day, and remained between 2 and 32 the second day for the Nal-R strains (E. coli and Klebsiella).(ABSTRACT TRUNCATED AT 250 WORDS)