Ehrmann S, Helms J, Joret A, et al. - Researchers examined a large intensive-care unit cohort to define nephrotoxic drug prescription and assessed the association of nephrotoxic prescription burden with acute kidney injury (AKI) via a case-control study nested in the prospective cohort. At least one nephrotoxic drug was prescribed to 617 patients (62%), and 303 (30%) of these were prescribed two or more. In 609 patients (61%), AKI was detected. Patients with developing or worsening AKI a given index day during the first week in the ICU were regarded as cases (n = 351), and patients not developing or worsening AKI during the first week in the ICU, alive the case index day, were controls. They computed drug.days: each drug and each day of therapy increasing the burden by 1 drug.day, to determine the nephrotoxic burden before the index day. Cases vs controls had a significantly higher nephrotoxic burden. Via calculating drug.day nephrotoxic burden, the assessment of frequently observed prescription of nephrotoxic drugs to critically ill patients may be done semi-quantitatively. This index (drug.day nephrotoxic burden) showed a significant link with subsequent AKI occurrence and worsening among patients with lower severity of disease.