Consensus guidelines for therapeutic drug monitoring in neuropsychopharmacology: Update 2017

Abstract

Therapeutic drug monitoring (TDM) is the quantification and interpretation of drug concentrations in blood to optimize pharmacotherapy. TDM is a valuable tool of precision medicine. It considers the high interindividual variability of pharmacokinetics and thus enables personalized pharmacotherapy. Non-response at therapeutic doses, uncertain drug adherence (compliance), suboptimal tolerability, or pharmacokinetic drug-drug interactions are typical indications for TDM. In psychiatry and neurology, patient populations that may particularly benefit from TDM are children and adolescents, pregnant women, elderly patients, individuals with intellectual disabilities, substance abuse disorders, forensic psychiatric patients or patients with known or suspected pharmacokinetic abnormalities or pharmacokinetically relevant comorbidities. The potential benefits of TDM for optimization of pharmacotherapy can only be obtained if the method is adequately integrated in the clinical treatment process. The interdisciplinary TDM task force of the working group on neuropsychopharmacology (Arbeitsgemeinschaft für Neuropsychopharmakologie und Pharmakopsychiatrie, AGNP) has updated the guidelines now: Therapeutic and dose related reference ranges, laboratory alert levels, indications and levels of recommendation to use TDM were reevaluated and updated for more than 154 neuropsychiatrie compounds. Moreover, supportive information on cytochrome P450 substrate, inhibitor and inducer properties of drugs and normal ranges of metabolite-to-parent concentration ratios, required for the interpretation of results from the laboratory, were updated. Recommendations are given when and how TDM should be combined with pharmacogenetic tests for cytochrome P450 enzymes and drug transporters. Following these guidelines holds the potential to improve the outcome of neuropsychopharmacotherapy, accelerate the recovery of many patients, especially in case of pharmacokinetic problems, and reduce health care costs.