Skip to content

Drug interactions

Hydroxychloroquine + Toremifene

Severity: Major

Hydroxychloroquine and Toremifene: 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

Toremifene carries a boxed warning for dose-dependent QT prolongation, and hydroxychloroquine also prolongs the QT interval. Combined use substantially raises the risk of torsades de pointes.

What this interaction means in plain words

Hydroxychloroquine and Toremifene 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; Toremifene belongs to Endocrine.

Evidence level: Moderate

Why it happens

Additive QT prolongation through pharmacodynamic effects.

What to do

Avoid the combination; if therapy with both is essential, monitor ECG and electrolytes closely and consider an alternative to toremifene.

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.

Pro+ members

Unlock the full page

Create an account and start a Pro+ trial to unlock the full management advice for Hydroxychloroquine and Toremifene, the additional notes, the evidence detail and the whole-prescription interaction checker.

  • Full clinical management advice
  • Additional notes
  • Evidence detail
  • Interaction checker for a whole prescription

Try Pro+ free for 7 days on the web. No card needed.

Frequently asked questions

Can I take Hydroxychloroquine with Toremifene?

MediHelp rates the interaction as major. Hydroxychloroquine and Toremifene 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. Toremifene carries a boxed warning for dose-dependent QT prolongation, and hydroxychloroquine also prolongs the QT interval. Combined use substantially raises the risk of torsades de pointes.

How serious is the interaction between Hydroxychloroquine and Toremifene?

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; if therapy with both is essential, monitor ECG and electrolytes closely and consider an alternative to toremifene.

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.

Full monographs, dosing and an interaction checker in the MediHelp app

Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.

Browse A–Z · Drug interactions

Get the app Sign in