Drug interactions
Lomitapide + Zafirlukast
Severity: Major
Lomitapide and Zafirlukast: major 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
Lomitapide is highly dependent on CYP3A4 for clearance, and its exposure rises substantially with inhibitors, increasing hepatotoxicity and gastrointestinal adverse effects. Zafirlukast is a weak inhibitor, which labeling for lomitapide treats as requiring a dose cap.
What this interaction means in plain words
Lomitapide and Zafirlukast can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Lomitapide belongs to Cardiovascular; Zafirlukast belongs to Respiratory.
Why it happens
CYP3A4 inhibition by zafirlukast reduces first-pass and systemic metabolism of lomitapide.
What to do
Limit the lomitapide dose to the labeled maximum for use with weak CYP3A4 inhibitors, or separate dosing as labeled, and monitor liver enzymes and gastrointestinal tolerability.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Zafirlukast
- Pimozide + Zafirlukast Contraindicated
- Nilotinib + Zafirlukast Major
- Warfarin + Zafirlukast Major
- Apalutamide + Zafirlukast Moderate
- Carbamazepine + Zafirlukast Moderate
- Conivaptan + Zafirlukast Moderate
Other interactions of Lomitapide
- Aprepitant + Lomitapide Contraindicated
- Clarithromycin + Lomitapide Contraindicated
- Crizotinib + Lomitapide Contraindicated
- Diltiazem + Lomitapide Contraindicated
- Efavirenz + Lomitapide Contraindicated
- Ensitrelvir + Lomitapide Contraindicated
Frequently asked questions
Can I take Lomitapide with Zafirlukast?
MediHelp rates the interaction as major. Lomitapide and Zafirlukast can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Lomitapide is highly dependent on CYP3A4 for clearance, and its exposure rises substantially with inhibitors, increasing hepatotoxicity and gastrointestinal adverse effects. Zafirlukast is a weak inhibitor, which labeling for lomitapide treats as requiring a dose cap.
How serious is the interaction between Lomitapide and Zafirlukast?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Limit the lomitapide dose to the labeled maximum for use with weak CYP3A4 inhibitors, or separate dosing as labeled, and monitor liver enzymes and gastrointestinal tolerability.
What other medicines interact with Zafirlukast?
MediHelp also lists interactions of Zafirlukast with, for example, Pimozide, Nilotinib, Warfarin. The full list is on the Zafirlukast page.
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