[Risperidone intoxication in a patient with a genetic predisposition as "poor [non]metabolizer"].
OBJECTIVE
The enzyme system cytochrome P450 plays a central role in the metabolism of drugs in the human body. The enzyme CYP2D6 is important for the metabolism of psychoactive agents. Genetic changes in the CYP2D6 gene can lead to reduced or absent activity.


METHODS
We report on a 37-year-old female patient who was given risperidone to treat an acute delusional disorder. Despite receiving a very low dose, the patient suffered from an intoxication. We inferred that an excessively raised plasma level of risperidone may result from a pharmacologically relevant disorder of metabolism.


RESULTS
The molecular genetic investigation revealed a compound heterozygous mutation in the CYP2D6 gene and thus documented a genetic predisposition as a "poor [non]metabolizer".


CONCLUSIONS
In intoxications with psychoactive agents, the presence of an enzyme defect in the P450 system should be considered as an additional possible cause.
Department für psychische Gesundheit, Klinik und Poliklinik für Psychiatrie, Universität Leipzig, Leipzig. Maria.Strauss@medizin.unileipzig.de
Maria
M
Strauss
Wolfram
W
Heinritz
Ulrich
U
Hegerl
Andrea
A
Kopf
D000328:Adult; D014150:Antipsychotic Agents / Q000493:pharmacokinetics* / Q000627:therapeutic use / Q000633:toxicity*; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics; D003511:Cyclohexanols / Q000493:pharmacokinetics / Q000627:therapeutic use; D019389:Cytochrome P-450 CYP2D6 / Q000235:genetics*; D004252:DNA Mutational Analysis; D003702:Delusions / Q000097:blood / Q000188:drug therapy* / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D016903:Drug Monitoring; D004359:Drug Therapy, Combination; D005091:Exons / Q000235:genetics; D005260:Female; D006580:Genetic Carrier Screening; D006801:Humans; D008658:Inactivation, Metabolic / Q000235:genetics; D007438:Introns / Q000235:genetics; D008657:Metabolic Clearance Rate; D011618:Psychotic Disorders / Q000097:blood / Q000188:drug therapy* / Q000235:genetics; D018967:Risperidone / Q000493:pharmacokinetics* / Q000627:therapeutic use / Q000633:toxicity*; D017367:Selective Serotonin Reuptake Inhibitors / Q000009:adverse effects / Q000627:therapeutic use; D000069470:Venlafaxine Hydrochloride
D014150:Antipsychotic Agents; D003511:Cyclohexanols; D019389:Cytochrome P-450 CYP2D6; D018967:Risperidone; D017367:Selective Serotonin Reuptake Inhibitors; D000069470:Venlafaxine Hydrochloride
Risperidonintoxikation bei genetischer Disposition als "poor [non]metabolizer".