IntroductionThe polymyxin group of polypeptide antibiotics is among the first antibiotics, discovered in the 1940s, with significant activity against gram-negative bacteria. Both polymyxin E (colistin) and polymyxin B were used clinically. Following reports on nephrotoxicity and neurotoxicity in the 1970s, other antibiotics were used instead of them. In the last decade, this group was reconsidered as a therapeutic option for multidrug-resistant/extremely drug-resistant gram-negative (MDR/XDR-GN) bacterial infections and particularly for the carbapenem-resistant Acinetobacter species (1,2).After its reintroduction in medical practice in the last 5 years, studies focused on the effectiveness and the side effects of colistin, especially nephrotoxicity. Nephrotoxicity after intravenous colistin treatment was observed at rates of 6%-58% in recent studies. Rates of 10%-27% and 58% were found in patients with basal normal and abnormal renal functions, respectively (3,4).The difference in the nephrotoxicity rates was explained by various definitions of acute kidney injury. Some studies used RIFLE criteria (risk, injury, failure, loss, and endstage kidney disease), while some used the threshold of failure or creatinine level of more than 2 mg/dL. Risk factors for nephrotoxicity were older age, preexisting renal insufficiency, hypoalbuminemia, hyperbilirubinemia, and concomitant use of nonsteroidal antiinflammatory drugs, calcineurin inhibitors, or other nephrotoxic agents like vancomycin (1,5,6).In this study, the efficiency against nosocomial MDR/ XDR-GN bacterial infections and risk of nephrotoxicity with intravenous colistin treatment were investigated.
Materials and methods
Study designThis retrospective study includes the records of patients treated with intravenous colistin between January 2011 and February 2013 in Celal Bayar University Hospital in Background/aim: Colistin is used as a salvage therapy for multidrug-resistant and extremely drug-resistant gram-negative bacterial infections. Our aim was to evaluate colistin efficiency and toxicity in the treatment of these resistant gram-negative bacterial infections.
Materials and methods:This is a retrospective study carried out in a tertiary care hospital during 2011-2013. Study data were collected from the medical records and consultations of the infectious diseases clinic.
Results:The study group included 158 patients with nosocomial infections and 136 (86.1%) of them were hospitalized in the ICU. Respiratory tract infections were the most commonly observed ones (n = 103, 65.2%). The most frequently isolated microorganism was Acinetobacter baumannii (72.2%). A total of 98 (62.0%) patients had clinical cure. There was no statistically significant difference between monotherapy (n = 3/6, 50.0%) and combination therapies (n = 95/152, 62.5%) according to clinical response. Underlying ultimately fatal disease, previous renal disease, and total parenteral nutrition were independent risk factors for poor clinical response. Nephrotoxicity developed in 80 (50.6%) patients...