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Cytochrome P450-mediated interaction between perazine and risperidone: implications for antipsychotic polypharmacy
Michael Paulzen1, Ekkehard Haen2, Christoph Hiemke3
1Department of Psychiatry, Psychotherapy and Psychosomatics, and JARA - Translational Brain Medicine, RWTH Aachen University, Aachen, Germany.
Combining antipsychotics like risperidone (RIS) and perazine increases drug interaction risks. Perazine significantly elevates RIS plasma levels and alters its metabolism, potentially by inhibiting CYP enzymes.
Area of Science:
- Pharmacology
- Psychiatry
- Drug Metabolism
Background:
- Antipsychotic polypharmacy lacks robust scientific evidence.
- Combining antipsychotics can lead to dangerous drug-drug interactions and adverse reactions.
Purpose of the Study:
- To investigate pharmacokinetic interactions between risperidone (RIS) and perazine.
- To assess the impact of perazine on risperidone plasma concentrations and metabolism.
Main Methods:
- Utilized a therapeutic drug monitoring database for plasma concentrations of RIS and 9-hydroxyrisperidone (9-OH-RIS).
- Compared two groups: RIS monotherapy (n=40) and RIS with perazine (n=16), matched for demographics and RIS dosage.
- Analyzed plasma concentrations, dose-corrected concentrations (C/D), and metabolic ratios (9-OH-RIS/RIS) using nonparametric tests.
Main Results:
- Patients on perazine showed significantly higher plasma concentrations and C/D values for RIS and its active moiety.
- The metabolic ratio of 9-OH-RIS/RIS was significantly lower in the perazine group.
- These changes suggest altered cytochrome P450 (CYP) enzyme activity, particularly CYP2D6.
Conclusions:
- Coadministration of perazine with risperidone increases RIS plasma concentrations and alters its metabolic ratio.
- Perazine likely inhibits CYP2D6 and CYP3A4, impacting risperidone metabolism.
- Findings highlight potential pharmacokinetic interactions in antipsychotic polypharmacy.
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