Comparative study of pharmacokinetics/ pharmacodynamics of ciprofloxacin between 400 mg intravenously every 8 h and 400 mg intravenously every 12 h in patients with gram negative bacilli bacteremia.
OBJECTIVE
To compare the ratio of the area under the concentration-time curve at 24 hours to the minimum inhibitory concentration value (24-h AUC/MIC) of ciprofloxacin between 400 mg intravenously every 8 h and 400 mg intravenously every 12 h.


METHODS
A prospective, randomized, two-way crossover study of 10 patients with gram-negative bacilli bacteremia was conducted. All patients were randomized to receive ciprofloxacin in both regimens consecutively: (i) 400 mg intravenously every 8 h for four doses; (ii) 400 mg intravenously every 12 h for four doses. Ciprofloxacin pharmacokinetic studies were carried out after the start of both regimens.


RESULTS
For the ciprofloxacin 400 mg intravenously every 8 h regimen, the 24-h AUC/MIC at MICs of 0.5 and 1 microg/ml were 218.63 +/- 78.75 and 109.31 +/- 39.37, respectively. For the ciprofloxacin 400 mg intravenously every 12 h regimen, the 24-h AUC/MIC at MICs of 0.5 and +/- microg/ml were 144.07 +/- 57.02 and 72.03 +/- 28.51, respectively. After 14 days of ciprofloxacin treatment, the gram-negative bacilli infections were eradicated in all patients. Moreover, during both regimens, no adverse events related to the use of ciprofloxacin were observed.


CONCLUSIONS
Both ciprofloxacin 400 mg every 8 h and 400 mg every 12 h regimens can provide good coverage for pathogens with the susceptibility breakpoint of ciprofloxacin with an MIC of 0.5 microg/ml. For pathogens with an MIC of 1.0 microg/ml, only ciprofloxacin 400 mg every 8 h regimen can provide a 24-h AUC/MIC ratio greater than 100.
Saengsuwan
Phanvasri
P
Department of Medicine, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand.
Jaruratanasirikul
Sutep
S
Jullangkoon
Monchana
M
Aeinlang
Nanchanit
N
D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000494:pharmacology*; D019540:Area Under Curve; D001407:Bacillus / Q000187:drug effects* / Q000302:isolation & purification; D016470:Bacteremia / Q000188:drug therapy / Q000382:microbiology; D002939:Ciprofloxacin / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000494:pharmacology*; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D005260:Female; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008826:Microbial Sensitivity Tests; D011446:Prospective Studies; D013997:Time Factors; D016896:Treatment Outcome
D000890:Anti-Infective Agents; D002939:Ciprofloxacin