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Drug interactions

Hydroxychloroquine + Pimavanserin

Severity: Major

Hydroxychloroquine and Pimavanserin: 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

Both drugs can prolong the QT interval, so giving them together may produce additive prolongation and raise the risk of torsades de pointes. The risk is greater with electrolyte disturbances, bradycardia or existing cardiac disease.

What this interaction means in plain words

Hydroxychloroquine and Pimavanserin 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.

Hydroxychloroquine belongs to Musculoskeletal; Pimavanserin belongs to Central Nervous System.

Evidence level: Moderate

Why it happens

Additive QT prolongation through cardiac repolarization (hERG potassium channel) effects.

What to do

Avoid the combination where possible and choose an alternative with less QT effect. If it is unavoidable, obtain a baseline and follow-up ECG and correct potassium and magnesium.

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 Hydroxychloroquine with Pimavanserin?

MediHelp rates the interaction as major. Hydroxychloroquine and Pimavanserin 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. Both drugs can prolong the QT interval, so giving them together may produce additive prolongation and raise the risk of torsades de pointes. The risk is greater with electrolyte disturbances, bradycardia or existing cardiac disease.

How serious is the interaction between Hydroxychloroquine and Pimavanserin?

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 choose an alternative with less QT effect. If it is unavoidable, obtain a baseline and follow-up ECG and correct potassium and magnesium.

What other medicines interact with Hydroxychloroquine?

MediHelp also lists interactions of Hydroxychloroquine with, for example, Arsenic trioxide, Cisapride, Dronedarone. The full list is on the Hydroxychloroquine page.

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