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Drug interactions

Chloroquine + Perphenazine

Severity: Major

Chloroquine and Perphenazine: major interaction.

Last updated Sources: UK SmPC

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

Perphenazine is metabolized by CYP2D6 and can prolong QT, while chloroquine inhibits CYP2D6 and also prolongs QT. The combination may raise perphenazine levels and increase the risk of arrhythmia and extrapyramidal effects.

What this interaction means in plain words

Chloroquine and Perphenazine 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.

Chloroquine belongs to Anti Parasitic; Perphenazine belongs to Central Nervous System.

Evidence level: Moderate

Why it happens

Additive QT prolongation plus CYP2D6 inhibition reducing perphenazine metabolism.

What to do

Avoid if possible. If used together, monitor ECG, electrolytes and extrapyramidal symptoms and reduce the perphenazine dose as needed.

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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References

Frequently asked questions

Can I take Chloroquine with Perphenazine?

MediHelp rates the interaction as major. Chloroquine and Perphenazine 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. Perphenazine is metabolized by CYP2D6 and can prolong QT, while chloroquine inhibits CYP2D6 and also prolongs QT. The combination may raise perphenazine levels and increase the risk of arrhythmia and extrapyramidal effects.

How serious is the interaction between Chloroquine and Perphenazine?

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 if possible. If used together, monitor ECG, electrolytes and extrapyramidal symptoms and reduce the perphenazine dose as needed.

What other medicines interact with Chloroquine?

MediHelp also lists interactions of Chloroquine with, for example, Cisapride, Dofetilide, Dronedarone. The full list is on the Chloroquine page.

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