Clinical Pharmacokinetics

, Volume 58, Issue 3, pp 299–308 | Cite as

Therapeutic Drug Monitoring of Oral Anti-Hormonal Drugs in Oncology

  • Stefanie L. GroenlandEmail author
  • Merel van Nuland
  • Remy B. Verheijen
  • Jan H. M. Schellens
  • Jos H. Beijnen
  • Alwin D. R. Huitema
  • Neeltje Steeghs
Review Article


Oral anti-hormonal drugs are essential in the treatment of breast and prostate cancer. It is well known that the interpatient variability in pharmacokinetic exposure is high for these agents and exposure–response relationships exist for many oral anti-hormonal drugs. Yet, they are still administered at fixed doses. This could lead to underdosing and thus suboptimal efficacy in some patients, while other patients could be overdosed resulting in unnecessary side effects. Therapeutic drug monitoring (TDM), individualized dosing based on measured blood concentrations of the drug, could therefore be a valid option to further optimize treatment. In this review, we provide an overview of relevant clinical pharmacokinetic and pharmacodynamic characteristics of oral anti-hormonal drugs in oncology and translate these into practical guidelines for TDM. For some agents, TDM targets are not well established yet and as a reference the median pharmacokinetic exposure could be targeted (exemestane: minimum plasma concentration (Cmin) 4.1 ng/mL and enzalutamide: Cmin 11.4 mg/L). However, for most drugs, exposure–efficacy analyses could be translated into specific targets (abiraterone: Cmin 8.4 ng/mL, anastrozole: Cmin 34.2 ng/mL, and letrozole: Cmin 85.6 ng/mL). Moreover, prospective clinical trials have shown TDM to be feasible for tamoxifen, for which the exposure–efficacy threshold of its active metabolite endoxifen is 5.97 ng/mL. Based on the available data, we therefore conclude that individualized dosing based on drug concentrations is feasible and promising for oral anti-hormonal drugs and should be developed further and implemented into clinical practice.


Compliance with Ethical Standards


No funding was received for the preparation of this article.

Conflict of interest

Remy B. Verheijen is currently a full-time employee of AstraZeneca, Cambridge, UK. Although Jan H. M. Schellens is involved in Modra Pharmaceuticals, this article does not contain information that poses a conflict of interest as it does not examine any product of Modra Pharmaceuticals or products related to this spinout company. Stefanie L. Groenland, Merel van Nuland, Jos H. Beijnen, Alwin D. R. Huitema, and Neeltje Steeghs have no conflicts of interest directly relevant to the content of this article.


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Copyright information

© Springer International Publishing AG, part of Springer Nature 2018

Authors and Affiliations

  • Stefanie L. Groenland
    • 1
    Email author
  • Merel van Nuland
    • 2
  • Remy B. Verheijen
    • 2
  • Jan H. M. Schellens
    • 1
    • 3
  • Jos H. Beijnen
    • 2
    • 3
  • Alwin D. R. Huitema
    • 2
    • 4
  • Neeltje Steeghs
    • 1
  1. 1.Division of Medical Oncology, Department of Clinical PharmacologyThe Netherlands Cancer Institute-Antoni van LeeuwenhoekAmsterdamThe Netherlands
  2. 2.Department of Pharmacy and PharmacologyThe Netherlands Cancer Institute-Antoni van Leeuwenhoek and MC SlotervaartAmsterdamThe Netherlands
  3. 3.Department of Pharmaceutical SciencesUtrecht UniversityUtrechtThe Netherlands
  4. 4.Department of Clinical Pharmacy, University Medical CenterUtrecht UniversityUtrechtThe Netherlands

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