Therapeutic drug monitoring in the elderly

Therapeutic drug monitoring (TDM) is defined as the strategy by which the dosing regimen for a patient is guided by repeated measurements of plasma or serum drug concentrations. TDM is also used to confirm drug poisoning and toxicity, to diagnose adverse drug reactions, and to verify patient compliance with drug regimens. There is a scarcity of data about the use of TDM in treating the elderly, but general inferences can be made based on pharmacokinetic and pharmacodynamic studies in older populations and on investigations in younger individuals. Despite its important limitations TDM seems to be an important tool in drug therapy management in the elderly given the increased frequency of chronic medical conditions, polypharmacy, drug interactions, and the atypical presentation of adverse drug reactions in this population.