Efficacy and safety of higher-dose intravenous ciprofloxacin in severe hospital-acquired infections.

In an open prospective study, 54 patients in an interdisciplinary, operative, anesthesiologic intensive care unit were treated with intravenous ciprofloxacin for life-threatening infections. Secondary nosocomial pneumonias were the predominant infection in most patients. A total of 88 causative pathogens were isolated from 50 patients. The most commonly isolated organism was Pseudomonas aeruginosa; Serratia marcescens, Staphylococcus aureus, and Enterobacter sp. were also isolated. Pathogens could not be detected in four patients (three patients with pneumonia, one patient with urinary tract infection). Ciprofloxacin was administered intravenously, either 400 mg every 12 hours or, after a loading dose of 600 mg every 12 hours on Day 1, 400 mg every 12 hours on successive treatment days. A total of 44 patients were treated parenterally, four orally. An additional six patients received ciprofloxacin in both dosage forms as sequential therapy. Serum ciprofloxacin levels were determined by high-performance liquid chromatography in 17 patients. The serum concentrations and the elimination half-life were in accordance with values already published for parenteral doses of 200 and 500 mg ciprofloxacin. Ciprofloxacin clearance was linear even at the high dose (600 mg every 12 hours loading dose) and no cumulative effect was observed. Clinical outcome was very good. Cure was achieved in 21 patients, and clinical improvement occurred in 23 (favorable clinical response rate, 82 percent). Two patients did not respond to therapy, and eight patients were not evaluable. Adverse effects occurred in 12 patients: transient elevation of liver enzymes (seven patients), temporary increase in serum creatinine levels (two), convulsions (two), and exanthem (one). The treatment of severe infections in intensive care patients with higher doses of parenteral ciprofloxacin appears to be considerably more effective than therapy with the doses of intravenous ciprofloxacin recommended to date. Therefore, these preliminary results are the subject of an ongoing double-blind study.