Effects of Liver Disease on Drug Metabolism in Humans

Abstract Drug disposition in humans is influenced by its absorption, volume of distribution, metabolism, and elimination. Drug metabolism involves Phase I and II biotransformations, most of which occur in the human liver. This chapter focuses on how physiological states may affect hepatic metabolism and the impact of liver disease on drug handling. The liver is vulnerable to a wide variety of insults, but the repertoire of its response to injury is limited. Likewise, the functional consequences of liver disease on drug disposition are determined by the extent of the injury, as opposed to its etiology. Predicting drug metabolism in patients with liver disease is particularly challenging. No universal rule can be applied to the modification of drug dosages in patients with liver disease.