Drug interactions
Sildenafil + Zafirlukast
Severity: Minor
Sildenafil 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
Sildenafil is a CYP3A4 substrate, and zafirlukast may modestly increase its levels. This may increase headache, flushing and hypotension.
What this interaction means in plain words
Sildenafil 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.
Sildenafil belongs to Genitourinary; Zafirlukast belongs to Respiratory.
Why it happens
Weak inhibition of CYP3A4-mediated sildenafil metabolism by zafirlukast.
What to do
Start with a lower sildenafil dose in patients at risk of hypotension. Monitor blood pressure and tolerability.
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 Sildenafil
- Amyl nitrite + Sildenafil Contraindicated
- Atazanavir + Sildenafil Contraindicated
- Cobicistat + Sildenafil Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Sildenafil Contraindicated
- Glyceryl trinitrate pr + Sildenafil Contraindicated
- Isosorbide dinitrate + Sildenafil Contraindicated
Frequently asked questions
Can I take Sildenafil with Zafirlukast?
MediHelp rates the interaction as minor. Sildenafil 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. Sildenafil is a CYP3A4 substrate, and zafirlukast may modestly increase its levels. This may increase headache, flushing and hypotension.
How serious is the interaction between Sildenafil 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: Start with a lower sildenafil dose in patients at risk of hypotension. Monitor blood pressure and tolerability.
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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