1. Case report: Therapeutic drug monitoring and CYP2D6 phenoconversion in a protracted paroxetine intoxication
- Author
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Alena Damborská, Lenka Hanáková, Eva Pindurová, and Kateřina Horská
- Subjects
paroxetine ,poor and intermediate metabolizer ,CYP2D6 ,phenoconversion ,overdose ,case report ,Therapeutics. Pharmacology ,RM1-950 - Abstract
ObjectiveThe cytochrome P450 2D6 (CYP2D6) is an enzyme involved in the oxidative biotransformation of various widely used drugs, including paroxetine, a substrate and strong inhibitor of the enzyme. The aim is to report on a case of protracted intoxication with paroxetine after a single overdose in a genotype-predicted intermediate CYP2D6 metabolizer.ObservationA 49-year-old man was receiving chronic treatment for more than 6 years with paroxetine 60 mg/day for an indication of agoraphobia. The patient ingested fifty 20 mg tablets of paroxetine in a suicide attempt. The toxic plasma level, accompanied by delirium, persisted for approximately 1 month after the overdose. According to the genotype profile, the patient was evaluated as an intermediate metabolizer with reduced CYP2D6 enzyme activity.ConclusionAs a consequence of the suicide attempt with overdose and the chronic paroxetine treatment that preceded it, phenoconversion to a poor metabolizer with very low CYP2D6 enzyme activity is suggested as contributing to an extremely long intoxication accompanied by delirium. Prolonged monitoring over a standard 24 h of both physical symptoms and drug plasma levels, together with a genetic profile assessment and phenoconversion consideration, is recommended after a single overdose in patients chronically treated with paroxetine.
- Published
- 2024
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