Monitoring drug therapy in the intensive care unit

Drugs are among the most commonly administered therapeutic interventions received. In the intensive care unit (ICU), patients routinely receive more therapies than on general medical or surgical wards, and practitioners caring for these patients are presented with the challenge of monitoring each of these therapies for efficacy and toxicity. The goal of this article is to describe a conceptual approach that practitioners can use to monitor for drug efficacy and predictable and unpredictable adverse drug effects. Although therapeutic drug monitoring (TDM) assumes a relatively small role in the overall monitoring scheme, TDM is discussed because it serves an important function for a select group of agents.