Automated Interlaboratory Comparison of Therapeutic Drug Monitoring Data and Its Use for Evaluation of Published Therapeutic Reference Ranges

Optimisation of pharmacotherapy in psychiatry through therapeutic drug monitoring, molecular brain imaging and pharmacogenetic tests: Focus on antipsychotics

BACKGROUND

For psychotic disorders (i.e. schizophrenia), pharmacotherapy plays a key role in controlling acute and long-term symptoms. To find the optimal individual dose and dosage strategy, specialised tools are used. Three tools have been proven useful to personalise drug treatments: therapeutic drug monitoring (TDM) of drug levels, pharmacogenetic testing (PG), and molecular neuroimaging.

METHODS

In these Guidelines, we provide an in-depth review of pharmacokinetics, pharmacodynamics, and pharmacogenetics for 45 antipsychotics. Over 30 international experts in psychiatry selected studies that have measured drug concentrations in the blood (TDM), gene polymorphisms of enzymes involved in drug metabolism, or receptor/transporter occupancies in the brain (positron emission tomography (PET)).

RESULTS

Study results strongly support the use of TDM and the cytochrome P450 (CYP) genotyping and/or phenotyping to guide drug therapies. Evidence-based target ranges are available for titrating drug doses that are often supported by PET findings.

CONCLUSION

All three tools discussed in these Guidelines are essential for drug treatment. TDM goes well beyond typical indications such as unclear compliance and polypharmacy. Despite its enormous potential to optimise treatment effects, minimise side effects and ultimately reduce the global burden of diseases, personalised drug treatment has not yet become the standard of care in psychiatry.

The European Organisation of External Quality Assurance Providers in Laboratory Medicine (EQALM) Statement: guidelines for publishing about interlaboratory comparison studies (PubILC)

Data and results from interlaboratory comparison (ILC) studies, external quality assessment (EQA) and proficiency testing (PT) activities are important and valuable contributions both to the further development of all disciplines of medical laboratory diagnostics, and to the evaluation and comparison of in vitro diagnostic assays. So far, however, there are no recommendations as to which essential items should be addressed in publications on interlaboratory comparisons. The European Organization of External Quality Assurance Providers in Laboratory Medicine (EQALM) recognized the need for such recommendations, and these were developed by a group of experts. The result of this endeavor is the EQALM Statement on items recommended to be addressed in publications on interlaboratory comparison activities (PubILC), in conjunction with a user-friendly checklist. Once adopted by authors and journals, the EQALM Statement will ensure essential information and/or study-related facts are included within publications on EQA/PT activities.

The prevalence of off-label use and supratherapeutic blood levels of outpatient psychotropic medication in suicidal adolescents

Introduction

Adolescents with mental disorders show an increased risk of suicidal phenomena. Vice versa, suicidality is a serious adverse event of psychotropic drug therapy in adolescents. There are only a few new psychotropic agents approved for this young age group. We evaluated the (pre-pandemic) prevalence of off-label use as well as detailed blood concentrations of outpatient psychotropic medication and sex differences in a clinical population of suicidal adolescents.

Methods

The urine presence and serum levels of psychotropic substances of adolescents hospitalized due to their acute suicidality but without a known actual suicide attempt (i.e., no acute intoxication or serious self-injuries) were investigated routinely between 01.03.2017 and 31.01.2018. Urine (N = 205) and blood samples (N = 193) were taken at the beginning of closed inpatient admission, i.e., the results of the laboratory analysis reflect outpatient drug intake. The serum levels of psychopharmacological medication and OTC medication were measured.

Results

Our sample consists of 231 cases (boys: N = 54; girls: N = 177, ratio: 1:3.3), aged 12-17 years (average age: 15,4 years). The most prevalent psychiatric diagnoses were depressive episodes (54%) and adjustment disorders (25%), and girls were more often diagnosed with depressive disorders than boys (boy/girl ratio: 1:9.5, p < 0.0001). More than half of adolescents (56%) used at least one prescribed psychotropic drug at admission (24.8% ≥ two psychotropic drugs). Off-label use of second-generation antipsychotics was significantly more frequent than off-label use of antidepressants (85% vs. 31%, p < 0.01). Adolescents suffering from depressive disorders were significantly more often on-label treated than adolescents with neurotic or stress-related disorders (56% vs. 10%). Female cases with prescribed psychotropic drug use showed significantly more frequent supratherapeutic drug levels than male cases (5% vs. 27%, p < 0.05).

Conclusion

Female adolescents may have an increased risk of supratherapeutic blood levels, especially when outpatient prescribed psychotropic drugs are off-label used. Measurement of blood levels of outpatient-prescribed psychotropic drugs could be used to enhance the safety and efficacy of the individual psychopharmacological treatment of adolescent suicidal patients. There is an urgent need for more real-world evidence on the effective treatment of adolescents with psychotropic drugs.