Drug interactions
Carbamazepine + Zafirlukast
Severity: Moderate
Carbamazepine and Zafirlukast: moderate 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
Carbamazepine is metabolized by CYP3A4, so zafirlukast could theoretically raise its levels, but its weak inhibition makes this unlikely to matter. Carbamazepine itself may in turn lower zafirlukast levels through enzyme induction.
What this interaction means in plain words
Carbamazepine and Zafirlukast can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Carbamazepine belongs to Central Nervous System; Zafirlukast belongs to Respiratory.
Why it happens
Zafirlukast weakly inhibits CYP3A4, while carbamazepine induces CYP enzymes involved in zafirlukast clearance.
What to do
Monitor carbamazepine concentrations and for toxicity such as dizziness or ataxia. Also monitor asthma control for reduced zafirlukast effect.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Zafirlukast
- Pimozide + Zafirlukast Contraindicated
- Lomitapide + Zafirlukast Major
- Nilotinib + Zafirlukast Major
- Warfarin + Zafirlukast Major
- Apalutamide + Zafirlukast Moderate
- Conivaptan + Zafirlukast Moderate
Other interactions of Carbamazepine
- Artemether / lumefantrine + Carbamazepine Contraindicated
- Cabotegravir + Carbamazepine Contraindicated
- Carbamazepine + Delamanid Contraindicated
- Carbamazepine + Dienogest / estradiol valerate Contraindicated
- Carbamazepine + Doravirine Contraindicated
- Carbamazepine + Elbasvir / grazoprevir Contraindicated
Frequently asked questions
Can I take Carbamazepine with Zafirlukast?
MediHelp rates the interaction as moderate. Carbamazepine and Zafirlukast can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Carbamazepine is metabolized by CYP3A4, so zafirlukast could theoretically raise its levels, but its weak inhibition makes this unlikely to matter. Carbamazepine itself may in turn lower zafirlukast levels through enzyme induction.
How serious is the interaction between Carbamazepine and Zafirlukast?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor carbamazepine concentrations and for toxicity such as dizziness or ataxia. Also monitor asthma control for reduced zafirlukast effect.
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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