[Personalised pharmacotherapy in intensive care unit patients]

Critically ill patients need fast, effective and safe pharmacotherapy. The pharmacokinetics and pharmacodynamics of the administered drugs are influenced by numerous individual conditions. Genetic factors mainly determines drug metabolism. However, therapeutic decisions are not yet guided by genetic analyses. In elderly patients, the volume of distribution can be altered and renal elimination may be delayed. Drug-drug interactions involving current medications can increase the incidence of adverse effects from treatment in the intensive care unit. In early severe sepsis, plasma levels of water-soluble drugs can be decreased because of enhanced volume of distribution and increased renal clearance. Later on, drug elimination can be impaired by deterioration of liver and renal function. Furthermore, the pharmacokinetic effects of continuous renal replacement therapy have to be considered. Plasma levels of critically ill patients show increased variability in comparison with healthy subjects or other patient groups. The therapeutic effect of antibiotics and of many other drugs cannot be assessed immediately. As dosage of these medications cannot be guided by their clinical efficacy, insufficient exposure or overdosage accompanied by toxic side effects may result. Standard dose recommendations that were developed in healthy volunteers or noncritically ill patients must be adapted to individual conditions and requirements of critically ill patients.