PPIG and chronic kidney disease: The impact of CKD on non-renal clearance, particularly upon the function of CYP enzymes is now well recognized [5–7] and recommendations for drug dosing and interactions have been adjusted accordingly by the Food and Drug Administration (FDA) [8] The activity of the CYP enzymes may be similarly impaired in critically ill patients [3,9] and evidence suggests that acute kidney injury (AKI) may be implicated [10,11].