Drug removal by PEX depends on pharmacokinetics of each drug, as well as on PEX characteristics (duration, frequency, volume) and clinical parameters for each patient (malnutrition, organ dysfunction). The data on drug removal by plasma exchange and other apheresis techniques are limited, and published studies have low quality of evidence due to small number of patients (often case reports), heterogeneity (different clinical scenarios, treatment of poisoning vs evaluation of drug removal), different apheresis techniques, and different pharmacokinetics of the evaluated agents. The chapter evaluates different factors for drug removal and gives guide on medication use in PEX.