Aim: The study's long-term goals, such as determining supratherapeutic ranges according to age distributions
specific to the country, adjusting dosages for additional drugs used by patients in different disease
groups, and providing the opportunity for etiological studies in the light of diagnosis and drug metabolism
perspective, are of great importance in defining the study. Method: Population pharmacokinetics is a
method expressed to evaluate processes such as absorption, distribution, metabolism, and elimination of a
drug from an individual's blood-plasma concentration. In drug pharmacokinetic experiments, generating
data without considering any pharmacokinetic differences among patients prevents the measurement or
observation of variability among individuals in the population as a simple approach. The dose-concentration
relationship is crucial for individualized dose adjustment. Additionally, the impact of other drugs used
by the individual on metabolite levels and the metabolic interactions between drugs play a critical role in
the development of personalized treatments. Population approaches provide a foundation that benefits the
observation of these effects. The variability in drug metabolism among individuals forms one of the fundamental
building blocks of personalized treatment approaches, specifically through Therapeutic Drug Monitoring
(TDM), which plays an important role in determining the therapeutic range of drugs. Materials:
In this study, drug metabolism findings of patients served at NP Istanbul Brain Hospital between 2010 and
2022 were examined within the repository created along with other patient-specific parameters. Results
and Conclusion: The analysis results have been followed up longitudinally, partially demographically,
and retrospectively. Thanks to the repository of NP Istanbul Brain Hospital, population pharmacokinetic
analyses aimed in this study are being conducted for the first time globally and nationally in terms of
scope. The repository has been studied with TDM for individualized treatment methods, and within this
project, it is anticipated to perform phenotyping with the population pharmacokinetic approach.