Intraindividual Pharmacokinetic Variability: Focus on Small‐Molecule Kinase Inhibitors

The magnitude of interindividual pharmacokinetic variability (IIV) of a drug and the factors responsible for this variability are intensively studied before-and sometimes after-registration as crucial information in anticipating and understanding variability in toxicity and efficacy. However, there has been much less attention paid to intraindividual variability, reflecting random or systematic changes in an individual's pharmacokinetics over time. We have chosen to focus on small-molecule kinase inhibitors (SMKIs).