Drug dosing in acute renal failure: the role of renal replacement therapy in altering drug pharmacokinetics.

The combination of multiple medical problems requiring complex drug therapy with rapidly changing organ functions that lead to pharmacokinetic alterations makes drug regimen design in the intensive care unit challenging. Acute renal failure leads to even greater physiologic disturbances requiring additional pharmacologic, nutritional, and dialytic support. A variety of renal replacement modalities, both intermittent and continuous, are used to manage the solute, volume, and acid-base derangements of patients with acute renal failure. Renal replacement therapies differ in their impact on drug dosing. The clinician must consider the impact of both disease and treatment if drug prescribing is to be optimal. Principles of solute removal are reviewed and concepts of drug regimen design are discussed. A practical approach to drug prescribing in this setting is described. Examples of dose adjustments for intermittent and continuous renal replacement therapies are provided.