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Drug interactions

Fluphenazine + Mifepristone

Severity: Major

Fluphenazine and Mifepristone: 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

Mifepristone, particularly at the higher doses used for Cushing syndrome, prolongs the QT interval, and fluphenazine has similar effects. Together they may increase the risk of serious ventricular arrhythmias including torsades de pointes.

What this interaction means in plain words

Fluphenazine and Mifepristone 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.

Fluphenazine belongs to Central Nervous System; Mifepristone belongs to Endocrine.

Evidence level: Moderate

Why it happens

Additive QT prolongation; mifepristone also inhibits CYP3A4 and may raise concentrations of some co-administered drugs.

What to do

Prefer an alternative to one of the agents when possible. If used together, obtain baseline and follow-up ECGs and keep potassium and magnesium within 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?

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 Fluphenazine with Mifepristone?

MediHelp rates the interaction as major. Fluphenazine and Mifepristone 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. Mifepristone, particularly at the higher doses used for Cushing syndrome, prolongs the QT interval, and fluphenazine has similar effects. Together they may increase the risk of serious ventricular arrhythmias including torsades de pointes.

How serious is the interaction between Fluphenazine and Mifepristone?

MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Prefer an alternative to one of the agents when possible. If used together, obtain baseline and follow-up ECGs and keep potassium and magnesium within normal range.

What other medicines interact with Fluphenazine?

MediHelp also lists interactions of Fluphenazine with, for example, Arsenic trioxide, Dofetilide, Ibutilide. The full list is on the Fluphenazine page.

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