Pharmacokinetic Parameters of Ciprofloxacin (500 mg/5 mL) Oral Suspension in Critically Ill Patients with Severe Bacterial Pneumonia: A Comparison of Two Dosages

Abstract

The authors determined the pharmacokinetic parameters of a new immediate-release ciprofloxacin suspension in tube-fed intensive care patients with bacterial pneumonia, to compare two dosage regimens: 500 mg b.i.d and 750 mg b.i.d. in this prospective clinical trial. The 20 patients were critically ill and on mechanical ventilation and enteral feeding with bacterial pneumonia. They were randomized to receive two different ciprofloxacin dosages: 500 mg b.i.d (group 1) versus 750 mg b.i.d. (group 2). Blood samples were collected from these patients after reaching steady-state and the pharmacokinetic parameters were determined.

The mean (range) serum steady-state concentration at 2 h after enteral administration was: C_{max 500} = 2.6 (1.2-4.3) mg/L in group 1 and C_{max 750} = 3.5 (1.5-5.9) mg/L in group 2. The mean (range) calculated 12-h area under the serum concentration was high in both groups: AUC_{0-12 (500)} = 24.7 (12.9-36.2) mg.h/L in group 1 and AUC_{0-12 (750)} = 28.9 (18.3-47.5) mg.h/L in group 2. In conclusion, ciprofloxacin oral suspension was well absorbed via nasogastric route in intensive care patients with severe pneumonia, achieving reliable pharmacokinetic parameters for most of the pathogens and important cost reduction compared to intravenous delivery. However, with less susceptible pathogens such as Staphylococcus aureus or Pseudomonas aeruginosa, higher dosages than 750 mg b.i.d. should be given.