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Therapeutic Drug Monitoring and Clinical Toxicology
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Interview with Teun van Gelder

Teun van Gelder

This month our current President, Teun van Gelder, shares his vision for his term, in particular increasing involvement of prescribers with the activities of the Association and research in the field. We also hear about Teun’s dual role at the Erasmus Medical Centre, and the collaboration between several prominent IATDMCT members that bring together various disciplines to daily patient care.


Teun van Gelder
Internist-nephrologist, Department of Internal Medicine
Internist-clinical pharmacologist, Hospital Pharmacy Department
Erasmus Medical Center, Rotterdam, NL

Dr. van Gelder, could you share with us a little bit about what you would like to see achieved in your time as President, as an organization and as an impact in the field?

Let me first mention that I very much appreciate the support from the IATDMCT membership, in allowing me to be the President of this society for the next two years. The trust in me is a valuable thing, and if I still have that same trust at the end of 2019 it would mean I have done my job. So, that would be my first goal, to meet the expectations of the membership.
Furthermore, I am hoping to increase the involvement of medical doctors in IATDMCT. Our society has grown over the years thanks to the pioneering work of laboratory scientists, chemists, clinical pharmacologists and pharmacists. Techniques to quantify drugs and metabolites in blood and other matrices have been developed and implemented in laboratories serving clinical centers. Increasingly our community is involved in translating the concentration measurements into meaningful advice for the clinician. In order to further develop this interaction, it is important that more clinicians are involved in our projects. Furthermore, there is an increasing demand to provide evidence that our recommendations lead to improved outcomes. To be able to conduct sufficiently powered studies that provide high level evidence, prescribers need to be part of our team.

What technological innovations have entered into use during your career that have permitted a change, or evolution, in practice?
We utilize the RapidFire technology to achieve high throughput analysis. We currently use it primarily for immunosuppressants, anticonvulsants and busulfan. It is not amenable to every drug, and it has proven very useful for those drugs where we need the rapid turnaround time and there are few interferences.

Can you tell us a little bit about your respective roles? What is a typical day like for you?
At Erasmus Medical Center I have two positions, one as an internist-nephrologist in the Department of Internal Medicine, and one as an internist-clinical pharmacologist in the Hospital Pharmacy. As a nephrologist, I am involved in the care of transplant recipients, with a strong focus on TDM of immunosuppressive drugs, but when I am on call I am also responsible for general nephrology and dialysis patients. In the Hospital Pharmacy, I am responsible for Research & Education. I teach medical students, and I have 11 PhDs involved in projects that focus on TDM (of antibiotics, oncology drugs, immunosuppression) and pharmacogenetics. My days are typically full of meetings, patient care, teaching and (too many) other things. Very exciting, never a dull moment, the next day is always different from the previous one.

Is there anything that your laboratory does, or that is done at your hospital/centre, that you would consider innovative?
Erasmus Medical Center is a very inspiring environment, and is very research minded. Collaborations are stimulated and we recently entered the “Academic Center of Excellence for Pharmacology & Therapeutics”. Within this entity prominent IATDMCT members like Prof Ron van Schaik (Head of the Pharmacogenetics Lab), Dr Dennis Hesselink (Head of the Kidney Transplant Unit) and Dr Birgit Koch (Head of the Pharmacy Lab) are closely working together. Ron’s Lab is leading in pharmacogenetics research, and Birgit has developed novel assays for detection of antihypertensive drugs, immunosupressants and antipsychotics in dried blood spots, and ethanol metabolites in meconium and other matrices. Together with Brenda de Winter, Birgit and I have a couple of research projects on PK/PD, e.g. in palliative patients, ICU patients and children.

What technological innovations have entered into use during your career that have permitted a change, or evolution, in practice?
I started working as an MD in 1988. In these (almost) 30 years a lot has changed. Mass spectrometry has had a major impact on TDM. Even more spectacular is the technological advancement of genotyping. The Human Genome Project was launched in 1990 by the National Institutes of Health and it took about ten years to complete the sequencing of the 3.5 billion human DNA base pairs. The subsequent explosion of molecular biology has led to enormous advances in DNA sequencing, which can now be done at incredible speed and for low cost. Now the implementation of all this knowledge needs to take place.

How did you become interested in your area of expertise?
As a young nephrologist, I was involved in the development of mycophenolate mofetil as a new drug for the transplant field. More or less by chance, I was offered the possibility to become the study site coordinator for a TDM study in kidney transplant patients. This study was a double-blind concentration controlled trial, with very complicated study logistics. I loved it. This was the start of my love affair with TDM. After I finished my nephrology training and my PhD I spent 18 months at Stanford University in the US (Randall E Morris’ lab, and collaborations with Uwe Chrstians who was at UCSF at that time) where my interest in clinical pharmacology grew even more. When I returned to the Netherlands I also got a degree in clinical pharmacology. I have been very lucky that Rotterdam has offered me the possibility to combine the two specialties.

Is there anything that you’ve seen or heard about recently and thought “I’d like to incorporate that idea at my center”?
I really love the close interaction between the lab and the clinic. I have seen examples from several groups where a laboratory measurement is generated into a dose recommendation using PK/PD modeling, and communicated with fancy dashboards. That’s something I would love to have at my center.

What sort of research do you have on the horizon that you think might influence clinical practice in the future?
As mentioned above I think it is crucial that we demonstrate the added value of what we do with appropriately designed clinical trials. It is not easy to change the way health care providers deal with drug dosing. If we want them to change their dosing strategy we need to come up with evidence of added value. Although of great importance for the laboratory side, medical doctors do not get excited from high precision or excellent quality controls. We need to show that, with our help, targets are reached more quickly, in more patients and that this improves clinical outcome. With this evidence, we will be using TDM a lot more in fields like oncology and infectious diseases.

What do you consider is the future for TDM and CT? What are you excited about? What are the challenges we face?
The future is bright, and not only because of the growing Young Scientists community within IATDMCT. There is a strong realization that it is necessary to reconsider the traditional ways we have dealt with choosing the right drug or the right dose. Also, patients are more demanding, and do not take a one size fits all approach for granted. We live in a society that asks for outperformance, and we can provide it.

The content of the IATDMCT Blog does not necessarily have the endorsement of the Association.