Case Report: Pharmacogenetics Applied to Precision Psychiatry Could Explain the Outcome of a Patient With a New CYP2D6 Genotype

Elena Marcos-Vadillo,María Isidoro-García,Ignacio Ramos-Gallego,Andrea Gaedigk,Belén García-Berrocal,Almudena Sánchez,Alfonso Sevillano-Jiménez,Manuel Franco-Martín,Eduardo Mayor-Toranzo,Lorena Carrascal-Laso

doi:10.3389/fpsyt.2021.830608

Abstract

Precision medicine applied to psychiatry provides new insight into the promising field of precision psychiatry. Psychotic disorders are heterogeneous, complex, chronic, and severe mental disorders. Not only does the prognosis and the course of the disease vary among patients suffering from psychotic disorders, but the treatment response varies as well. Although antipsychotic drugs are the cornerstone of the treatment of schizophrenia, many patients only partially respond to these drugs. Furthermore, patients often experience adverse events which can lead to poor treatment adherence. Interindividual variability in drug response could be related to age, gender, ethnicity, lifestyle factors, pharmacological interactions, obesity, and genetics, all of which influence the process of drug metabolism. Commonly prescribed antipsychotics are metabolized by cytochrome P450 (CYP450) enzymes, and CYP450 genes are highly polymorphic. Pharmacogenetic testing is increasingly being used to predict a patient's drug response and could help to find the most appropriate therapy for an individual patient. In this report, we describe a psychotic patient who did not receive adequate clinical follow-up and subsequently presented adverse events, which could be explained by his pharmacogenetic profile and the drug interactions resulting from the polypharmacy prescribed.

Highlights

An increasing number of children, adolescents, and adults [1] are being diagnosed with mental illness, including depressive disorder, bipolar disorder, and schizophrenia spectrum disorder [2,3,4,5,6,7]
For pharmacogenetic interactions. 2nd treatment plan (18/01/2016–13/06/2016): Based on the adverse effect referred by the patient and taking into account his poor clinical progress during the last hospitalization, the prescriber adjusted the drug treatment upon the patient’s release to only include lithium and amisulpride, neither of which is metabolized by a CYP enzyme
The patient presented extrapyramidal symptoms after administration of haloperidol due to a manic episode managed as an outpatient. 7th treatment plant: Given the need to control the patient’s sleep pattern and in light of the sedative effects of olanzapine, olanzapine was replaced with aripiprazole, eventually a long-acting injectable (LAI), to ensure adherence and simplify the absorption variables, complementing the therapy with lithium, clonazepam, lormetazepam, and pregabalin

Summary

INTRODUCTION

An increasing number of children, adolescents, and adults [1] are being diagnosed with mental illness, including depressive disorder, bipolar disorder, and schizophrenia spectrum disorder [2,3,4,5,6,7]. 2nd treatment plan (18/01/2016–13/06/2016): Based on the adverse effect referred by the patient and taking into account his poor clinical progress during the last hospitalization, the prescriber adjusted the drug treatment upon the patient’s release to only include lithium and amisulpride, neither of which is metabolized by a CYP enzyme. 7th treatment plant (from December 2017): Given the need to control the patient’s sleep pattern and in light of the sedative effects of olanzapine, olanzapine was replaced with aripiprazole, eventually a long-acting injectable (LAI), to ensure adherence and simplify the absorption variables, complementing the therapy with lithium, clonazepam, lormetazepam, and pregabalin From this point, the patient did not present AE, nor needed hospitalization

DISCUSSION

Findings

ETHICS STATEMENT