Due to the emerging antibiotic resistance of Acinetobacter, which is the leading cause of ventilator-associated pneumonia (VAP) in critically ill patients, there is an urgent need for studies comparing various antibiotic regimens for its treatment. In this single blinded randomized clinical trial, adult patients with VAP due to multi drug resistant Acinetobacter (MDRA), were randomly assigned to receive 9×109 unit loading dose of colistin followed by 4.5×109 unit intravenously twice daily plus 750 mg intravenous levofloxacin daily or continuous infusion of ampicillin/sulbactam, 24g daily plus 750mg IV levofloxacin daily. Dose and dosing interval were adjusted according to serum creatinine levels during the study. Clinical and microbiological cure, inflammatory biomarkers, and possible adverse effects were recorded in participants. Twenty-nine patients were recruited (14 in colistin and 15 in ampicillin/sulbactam groups). Three patients were excluded in each group. Clinical response occurred in 3 (27%) and 10 (83%) in colistin and ampicillin-sulbactam arms, respectively (P = 0.007). Nephrotoxicity happened in 6 (54%) and 1 (8%) of cases in colistin and ampicillin-sulbactam groups, (P = 0.016). 14-day and 28-day survival rate were significantly higher in ampicillin-sulbactam group compared to colistin arm with P values of 0.002 and 0.049, respectively. This study revealed that levofloxacin plus high dose ampicillin/sulbactam as continuous infusion is more effective than levofloxacin plus colistin in patients with MDR Acinetobacter VAP with significantly lower risk of nephrotoxicity.
Keywords: Acinetobacter; Ampicillin-Sulbactam; Levofloxacin; Pneumonia; Ventilator-Associated; colistin.