Drug dosing according to renal function is a globally accepted practice whose main purpose is to avoid drug associated toxicity when renal clearance is decreased. Renal function is usually estimated based on creatinine clearance or an estimated glomerular filtration rate (GFR) obtained from one of the available equations based on serum biomarkers. In this review we will analyze the different available methods to adjust the dose of drugs based on GFR, with emphasis on their comparative performance for this objective. Based on this, we will provide some recommendations for drug dosing in chronic and acute renal dysfunction.