Safety and efficacy with colistin use: a South African tertiary level experience

Abstract

Background: Clinical experience with colistin, one of the last resort agents against multi-drug resistant gram-negative bacteria (MDR-GNB), shows clinical response varying between 45% to 88%. Two previous South African studies have shown in-hospital mortality rates to vary between 29.6% and 50%. There is also a considerable variation in nephrotoxic potential of colistin which ranges between 20% to 60%. No studies examine the safety and efficacy of colistin in a predominantly HIV infected adult population. Aim: To assess the safety and efficacy of colistin in a South African tertiary public health-care facility. Methods: We performed a retrospective review of adult patients treated with intravenous colistin at Chris Hani Baragwanath Academic Hospital (CHBAH) between June 2014 to May 2017. Patients were identified through Section 21 applications to the South African Health Products Regulatory Authority (SAHPRA). CHBAH hospital charts and microbiological laboratory records were also available. Demographics, clinical characteristics including features of infection, admitting departments, sites of cultures, the spectrum of organisms cultured, and specifics of therapy with colistin were all recorded. We reported clinical and microbiological outcomes, as well as the incidence of nephrotoxicity. Results: Of 118 patients treated (mean age of 42.4 years, with documented HIV positivity in 45 patients (38.1%)), favourable clinical and microbiological outcomes were seen in 70 patients (59.3%) and 71 patienCASts (74.5) respectively. Bacteraemia was noted in 77 patients (65.3%),and Acinetobacter baumannii and Klebsiella pneumoniae were the commonest organisms isolated from all sources and were cultured from 80 patients (67.8%) and 23 patients (19.5%) respectively. Clinical treatment failure was noted in 11 patients (9.3%), and 14-day-mortality was observed in 37 patients (31.4%). Logistic regression showed that HIV positivity was not associated with adverse outcomes, and male gender was significant for a favourable clinical outcome. Nephrotoxicity was found in 37 patients (31.4%). Conclusion: Colistin was effective in the treatment of MDR-GNB in our setting, and HIV positivity was not associated with an adverse outcome