Drug interactions
Formoterol + Levoketoconazole
Severity: Major
Formoterol and Levoketoconazole: major interaction.
Last updated Sources: US FDA label
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
Levoketoconazole prolongs the QT interval in a dose-related manner and carries a boxed warning for this. Formoterol may add to QT prolongation and lower potassium, increasing the risk of torsades de pointes.
What this interaction means in plain words
Formoterol and Levoketoconazole 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.
Formoterol belongs to Respiratory; Levoketoconazole belongs to Endocrine.
Why it happens
Additive QT prolongation (pharmacodynamic), with beta-2 agonist induced hypokalemia contributing.
What to do
Avoid the combination where possible and use an alternative bronchodilator. If it is unavoidable, monitor ECG and keep potassium and magnesium in the normal range.
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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References
Other interactions of Formoterol
- Adagrasib + Formoterol Major
- Amiodarone + Formoterol Major
- Amisulpride + Formoterol Major
- Amitriptyline + Formoterol Major
- Amoxapine + Formoterol Major
- Arformoterol + Formoterol Major
Other interactions of Levoketoconazole
- Alfuzosin + Levoketoconazole Contraindicated
- Alprazolam + Levoketoconazole Contraindicated
- Amiodarone + Levoketoconazole Contraindicated
- Avanafil + Levoketoconazole Contraindicated
- Cisapride + Levoketoconazole Contraindicated
- Clarithromycin + Levoketoconazole Contraindicated
Frequently asked questions
Can I take Formoterol with Levoketoconazole?
MediHelp rates the interaction as major. Formoterol and Levoketoconazole 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. Levoketoconazole prolongs the QT interval in a dose-related manner and carries a boxed warning for this. Formoterol may add to QT prolongation and lower potassium, increasing the risk of torsades de pointes.
How serious is the interaction between Formoterol and Levoketoconazole?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination where possible and use an alternative bronchodilator. If it is unavoidable, monitor ECG and keep potassium and magnesium in the normal range.
What other medicines interact with Formoterol?
MediHelp also lists interactions of Formoterol with, for example, Adagrasib, Amiodarone, Amisulpride. The full list is on the Formoterol page.
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