PurposePatients receiving colistin for carbapenem-resistant gram-negative bacteria (CR-GNB) infections generally have multiple risk factors for nephrotoxicity, so it might be possible that colistin may be erroneously blamed for the nephrotoxicity.Materials and methodsWe retrospectively analyzed case records of patients who received colistin and those who received antibiotics other than colistin [carbapenem or β-lactam–β-lactamases inhibitors (βL–βLI)] for gram-negative bacteremia. Those patients with preexisting renal failure and those who received antibiotics for <72 hours were excluded from the study. Nephrotoxicity was assessed using the risk of renal dysfunction, injury to the kidney, failure of kidney function, loss of kidney function, end-stage kidney disease (RIFLE) criteria.ResultsOut of the 222 patients, the colistin arm had 118 and the noncolistin arm had 104 patients. Even though the colistin arm had significantly higher number of sicker patients with neutropenia (40.7% vs 14.4%, p = 0.0001), mechanical ventilation (0.0001), having lines (0.0001), on inotropes (0.003), receiving other nephrotoxic drugs (0.0001), and higher Pitt score (p = 0.0001), there was no significant difference in the nephrotoxicity between the two arms (10.2% vs 9.6%, p = 0.89). Logistical regression showed a higher Pitt bacteremia score (p = 0.03) and a higher Charlson comorbidity index (p = 0.02), but not colistin administration (p = 0.32), were independently associated with nephrotoxicity.ConclusionAdministration of colistin was not associated with higher rates of nephrotoxicity than carbapenems or βL–βLI agents.How to cite this articleGhafur A, Bansal N, Devarajan V, Raja T, Easow J, Raja MA, et al. Retrospective Study of Nephrotoxicity Rate among Adult Patients Receiving Colistin Compared to β-lactam Antibiotics. IJCCM 2019;23(11):518–522.