Abstract
Background: Therapeutic drug monitoring (TDM) has traditionally relied on measured serum concentrations interpreted against predefined therapeutic ranges. This approach remains valuable for medications with narrow therapeutic indices but may inadequately account for substantial interindividual pharmacokinetic variability. Model-informed precision dosing (MIPD), particularly Bayesian forecasting, provides a framework for integrating drug concentrations with population pharmacokinetic models and patient-specific characteristics to individualize therapy.
Objective: To review contemporary TDM and pharmacokinetics-based dose individualization, with particular attention to Canadian practice and the transition from conventional concentration monitoring toward model-informed precision dosing.
Methods: A narrative review of contemporary pharmacokinetic literature, therapeutic monitoring guidance, Canadian hospital studies, institutional surveys, and studies evaluating Bayesian and model-informed dosing was undertaken.
Results: Canadian experience demonstrates both the established role of pharmacist-led TDM and important opportunities for modernization. In a national survey of 120 pharmacists from 10 Canadian provincial and territorial jurisdictions, approximately 90% of hospitals still used trough-based vancomycin monitoring, whereas only 10.1% reported AUC-based monitoring. Most hospitals had institutional vancomycin guidelines, and 80.7% reported medical directives allowing pharmacists to order concentrations and/or adjust doses autonomously. Canadian institutions have also developed open-source Bayesian vancomycin tools, investigated aminoglycoside monitoring practices, evaluated beta-lactam concentrations in critically ill patients, and optimized tacrolimus monitoring through pharmacist-led protocols. These examples illustrate the progression from concentration measurement toward individualized exposure-guided therapy.
Conclusion: TDM is evolving from interpretation of isolated drug concentrations toward individualized pharmacokinetic decision-making. Canadian experience highlights both strong pharmacist involvement and substantial variability in implementation. Wider adoption of MIPD will require validated models, clinical decision-support infrastructure, pharmacist training, integration with electronic health records, appropriate laboratory support, and evidence that improved exposure target attainment translates into meaningful patient outcomes.
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Ethics & Declarations
Author Contributions
All authors contributed to the study conception and design. Material preparation, data collection, and analysis were performed by all authors. All authors read and approved the final manuscript.
Ethics Approval and Consent to Participate
Not applicable. This study did not involve human participants, animal experimentation, or confidential patient clinical data.
Consent for Publication
Not applicable, or informed consent for publication was obtained from all individual participants where relevant.
Competing Interests
The authors declare that they have no competing financial or non-financial interests.
Funding
The authors declare that no funds, grants, or other financial support were received during the preparation of this manuscript.
Data Availability Statement
Data sharing is not applicable to this article as no new datasets were generated or analyzed during the current study.
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© 2026 Mohamed Abdellatif et al. International Journal of Clinical Pharmacy and Medicine.