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Drug interactions

Flecainide + Levoketoconazole

Severity: Major

Flecainide and Levoketoconazole: 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

Levoketoconazole prolongs the QT interval, and flecainide can add to proarrhythmic risk. It may also inhibit CYP enzymes including CYP2D6 weakly, which could raise flecainide exposure.

What this interaction means in plain words

Flecainide 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.

Flecainide belongs to Cardiovascular; Levoketoconazole belongs to Endocrine.

Evidence level: Low

Why it happens

Additive QT prolongation; possible pharmacokinetic increase in flecainide through CYP inhibition.

What to do

Avoid the combination where possible. If used, monitor ECG (QTc, QRS) closely and keep potassium and magnesium normal.

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?

Bring a full list of your medicines, including over-the-counter products, supplements and herbal remedies, to every pharmacy visit.

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Frequently asked questions

Can I take Flecainide with Levoketoconazole?

MediHelp rates the interaction as major. Flecainide 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, and flecainide can add to proarrhythmic risk. It may also inhibit CYP enzymes including CYP2D6 weakly, which could raise flecainide exposure.

How serious is the interaction between Flecainide 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. If used, monitor ECG (QTc, QRS) closely and keep potassium and magnesium normal.

What other medicines interact with Flecainide?

MediHelp also lists interactions of Flecainide with, for example, Nirmatrelvir, Nirmatrelvir / ritonavir, Pimozide. The full list is on the Flecainide page.

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