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
Phanvasri Saengsuwan MSc*, Sutep Jaruratanasirikul MD*, Monchana Jullangkoon MPharm*, Nanchanit Aeinlang MPharm*
Affiliation : * Department of Medicine, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand
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.
Material and Method: 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 μg/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 1 μg/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.
Conclusion : 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 μg/ml. For pathogens with an MIC of 1.0 μg/ml, only
ciprofloxacin 400 mg every 8 h regimen can provide a 24-h AUC/MIC ratio greater than 100.
Keywords : Ciprofloxacin, Pharmacokinetic/pharmacodynamic, 24-h AUC/MIC, Bacteremia
