Drug interactions
Propafenone + Zafirlukast
Severity: Minor
Propafenone 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
Propafenone is metabolized by CYP2D6, CYP3A4 and CYP1A2. A weak CYP3A4 effect from zafirlukast is unlikely to cause important change, but propafenone has a narrow therapeutic margin.
What this interaction means in plain words
Propafenone 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.
Propafenone belongs to Cardiovascular; Zafirlukast belongs to Respiratory.
Why it happens
Possible weak CYP3A4 inhibition by zafirlukast reducing propafenone clearance.
What to do
No empiric change is needed. Monitor ECG (PR and QRS intervals) and heart rate if both drugs are used.
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 Propafenone
- Dofetilide + Propafenone Contraindicated
- Dronedarone + Propafenone Contraindicated
- Nilotinib + Propafenone Contraindicated
- Nirmatrelvir / ritonavir + Propafenone Contraindicated
- Nirmatrelvir + Propafenone Contraindicated
- Pimozide + Propafenone Contraindicated
Frequently asked questions
Can I take Propafenone with Zafirlukast?
MediHelp rates the interaction as minor. Propafenone 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. Propafenone is metabolized by CYP2D6, CYP3A4 and CYP1A2. A weak CYP3A4 effect from zafirlukast is unlikely to cause important change, but propafenone has a narrow therapeutic margin.
How serious is the interaction between Propafenone 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 empiric change is needed. Monitor ECG (PR and QRS intervals) and heart rate if both drugs are used.
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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