Colistin use and outcomes in Kuwait public hospitals

Abstract

Background In Kuwait, colistin use has increased owing to an increased incidence of multidrug resistant infections. However, the optimal dosing regimen and its effectiveness and safety are unclear. We aimed to describe colistin use in Kuwait and evaluate the associated clinical outcomes and safety profiles. Methods This multicentre, retrospective, observational study used data collected from five hospitals. Study outcomes included cure rates, incidence of nephrotoxicity, and mortality. Logistic regression models were used to study the effect of colistin dosing patterns (loading dose, daily maintenance dose, and duration of therapy) on study outcomes. The models were adjusted for age, sex, and hospital unit (ICU/non-ICU), baseline creatinine clearance, being on dialysis, pathogen type, receiving concomitant antibiotics, and site of infection. Results Of 205 patients treated with colistin, 117 were treated in intensive care units (ICUs) and 88 were treated in other units. Of the 205 patients, 145 (70.7%) achieved clinical cure. The cure rate was lower in ICU patients than in non-ICU patients. Fifty patients experienced nephrotoxicity; 47 died, and 11 experienced neurotoxicity. The incidence of nephrotoxicity did not differ significantly by hospital unit, whereas the case fatality rate was significantly higher and the incidence of neurotoxicity was significantly lower in ICU patients. Administration of a loading dose was not associated with the cure rate, incidence of nephrotoxicity, or case fatality rate. Higher maintenance doses were associated with higher cure rates, (odds ratio [OR], 2.77; 95% confidence interval [CI], 1.04–7.37) and lower fatality rates (OR, 0.29; 95% CI, 0.09–0.95), but more likely to develop nephrotoxicity (OR, 2.60; 95% CI, 1.08–6.23). Conclusion Administration of high maintenance doses of colistin was associated with higher cure rates but was also associated with a higher incidence of nephrotoxicity.