Pharmacokinetics in the elderly.

The elderly are an expanding population of patients presenting for anaesthesia. The pharmacokinetics of anaesthetic agents in the elderly deserves special attention because the normal ageing process and the effect of age-related diseases affect organ systems in a heterogeneous way with unpredictable consequences. The pharmacokinetics of each drug is also affected by these changes in a specific way and, together with the pharmacodynamic consequences, makes drug use and drug dosing challenging in this population. Although a decrease in bolus and infusion rates is a common theme, only pharmacokinetic modelling of drug disposition in the elderly will provide accurate dosing guidelines and increase the margin of safety.