Drug interactions
Clozapine + Zafirlukast
Severity: Minor
Clozapine and Zafirlukast: minor 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
Clozapine is metabolized mainly by CYP1A2 with a contribution from CYP3A4, so zafirlukast is unlikely to change levels much. Any increase could add to sedation, hypotension or seizure risk.
What this interaction means in plain words
Clozapine and Zafirlukast have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Clozapine belongs to Central Nervous System; Zafirlukast belongs to Respiratory.
Why it happens
Weak CYP3A4 inhibition by zafirlukast may slightly reduce clozapine clearance.
What to do
No empirical adjustment. Monitor for sedation, hypotension and tachycardia, and check clozapine levels if toxicity is suspected.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Zafirlukast
- Pimozide + Zafirlukast Contraindicated
- Lomitapide + Zafirlukast Major
- Nilotinib + Zafirlukast Major
- Warfarin + Zafirlukast Major
- Apalutamide + Zafirlukast Moderate
- Carbamazepine + Zafirlukast Moderate
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 Zafirlukast?
MediHelp rates the interaction as minor. Clozapine and Zafirlukast have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Clozapine is metabolized mainly by CYP1A2 with a contribution from CYP3A4, so zafirlukast is unlikely to change levels much. Any increase could add to sedation, hypotension or seizure risk.
How serious is the interaction between Clozapine and Zafirlukast?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No empirical adjustment. Monitor for sedation, hypotension and tachycardia, and check clozapine levels if toxicity is suspected.
What other medicines interact with Zafirlukast?
MediHelp also lists interactions of Zafirlukast with, for example, Pimozide, Lomitapide, Nilotinib. The full list is on the Zafirlukast page.
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