Drug interactions
Mifepristone + Primaquine
Severity: Major
Mifepristone and Primaquine: 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
Mifepristone, at the higher doses used for Cushing syndrome, can prolong the QT interval and inhibit CYP3A4. Primaquine may add to the QT effect, and mifepristone may raise primaquine levels, increasing the risk of arrhythmia and toxicity.
What this interaction means in plain words
Mifepristone and Primaquine 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 belongs to Endocrine; Primaquine belongs to Anti Parasitic.
Why it happens
Additive QT prolongation plus CYP3A4 inhibition by mifepristone, which may increase primaquine exposure.
What to do
Avoid the combination where possible, particularly with chronic high-dose mifepristone. If it is used, check the ECG and electrolytes and monitor for hemolysis and other primaquine toxicity.
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 Primaquine
- Pimozide + Primaquine Contraindicated
- Amiodarone + Primaquine Major
- Amisulpride + Primaquine Major
- Anagrelide + Primaquine Major
- Arsenic trioxide + Primaquine Major
- Asenapine + Primaquine Major
Other interactions of Mifepristone
- Apixaban + Mifepristone Contraindicated
- Argatroban + Mifepristone Contraindicated
- Cisapride + Mifepristone Contraindicated
- Cortisone + Mifepristone Contraindicated
- Cyclosporin + Mifepristone Contraindicated
- Dabigatran etexilate + Mifepristone Contraindicated
Frequently asked questions
Can I take Mifepristone with Primaquine?
MediHelp rates the interaction as major. Mifepristone and Primaquine 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, at the higher doses used for Cushing syndrome, can prolong the QT interval and inhibit CYP3A4. Primaquine may add to the QT effect, and mifepristone may raise primaquine levels, increasing the risk of arrhythmia and toxicity.
How serious is the interaction between Mifepristone and Primaquine?
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, particularly with chronic high-dose mifepristone. If it is used, check the ECG and electrolytes and monitor for hemolysis and other primaquine toxicity.
What other medicines interact with Primaquine?
MediHelp also lists interactions of Primaquine with, for example, Pimozide, Amiodarone, Amisulpride. The full list is on the Primaquine page.
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