Drug interactions
Saquinavir + Zafirlukast
Severity: Moderate
Saquinavir 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
Saquinavir is a CYP3A4 substrate, and zafirlukast may slightly raise its levels. Saquinavir can prolong QT and PR intervals, so higher exposure is of some concern. The interaction is expected to be small.
What this interaction means in plain words
Saquinavir 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.
Why it happens
Weak CYP3A4 inhibition by zafirlukast may reduce saquinavir clearance.
What to do
Obtain an ECG if other QT-prolonging drugs are used or cardiac risk is present. Otherwise monitor for saquinavir adverse effects.
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
- Carbamazepine + Zafirlukast Moderate
Frequently asked questions
Can I take Saquinavir with Zafirlukast?
MediHelp rates the interaction as moderate. Saquinavir 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. Saquinavir is a CYP3A4 substrate, and zafirlukast may slightly raise its levels. Saquinavir can prolong QT and PR intervals, so higher exposure is of some concern. The interaction is expected to be small.
How serious is the interaction between Saquinavir 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: Obtain an ECG if other QT-prolonging drugs are used or cardiac risk is present. Otherwise monitor for saquinavir adverse effects.
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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