Variations of pharmacokinetics of drugs in patients with cirrhosis.

Liver cirrhosis is the end stage of many different chronic liver diseases and is becoming an important cause of mortality and morbidity across the world. In theory, the numerous physiopathological changes suffered by these patients warrant relevant pharmacokinetic changes in most drugs. However, the influence of these changes on the efficacy and toxicity responses of patients with cirrhosis have been evaluated by few clinical trials and observational studies. As a consequence, therapeutic decisions in these patients are usually complex and subject to uncertainties. In this article, we review the regulatory guidelines to study responses to drugs according to pharmacokinetic variability and the published information that is useful for guiding the dosage adjustment of frequently used drugs in patients with cirrhosis (antivirals, antibiotics, analgesics, etc.) to obtain the best risk-benefit ratio.