Drug interactions
Clozapine + Peginterferon alfa 2a
Severity: Major
Clozapine and Peginterferon alfa 2a: major interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Peginterferon alfa-2a inhibits CYP1A2, the main enzyme metabolizing clozapine, and may raise clozapine levels. Both drugs can also cause neutropenia, so hematologic toxicity may be additive.
What this interaction means in plain words
Clozapine and Peginterferon alfa 2a can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Clozapine belongs to Central Nervous System; Peginterferon alfa 2a belongs to Anti Virals.
Why it happens
CYP1A2 inhibition by peginterferon plus additive myelosuppression.
What to do
Monitor clozapine levels, sedation, seizures and cardiac effects, and reduce the dose as needed. Check absolute neutrophil counts more often.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Peginterferon alfa 2a
Other interactions of Clozapine
- Clozapine + Deferiprone Contraindicated
- Clozapine + Irinotecan Contraindicated
- Clozapine + Pimozide Contraindicated
- Clozapine + Thioridazine Contraindicated
- Acalabrutinib + Clozapine Major
- Adagrasib + Clozapine Major
Frequently asked questions
Can I take Clozapine with Peginterferon alfa 2a?
MediHelp rates the interaction as major. Clozapine and Peginterferon alfa 2a can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Peginterferon alfa-2a inhibits CYP1A2, the main enzyme metabolizing clozapine, and may raise clozapine levels. Both drugs can also cause neutropenia, so hematologic toxicity may be additive.
How serious is the interaction between Clozapine and Peginterferon alfa 2a?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor clozapine levels, sedation, seizures and cardiac effects, and reduce the dose as needed. Check absolute neutrophil counts more often.
What other medicines interact with Peginterferon alfa 2a?
MediHelp also lists interactions of Peginterferon alfa 2a with, for example, Deferiprone, Hydroxyurea, Pexidartinib. The full list is on the Peginterferon alfa 2a page.
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