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Drug interactions

Tacrolimus + Toremifene

Severity: Major

Tacrolimus 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

Both drugs can prolong the QT interval, so combined use raises the risk of torsades de pointes and other serious ventricular arrhythmias. The risk increases with electrolyte disturbances, bradycardia or underlying heart disease.

What this interaction means in plain words

Tacrolimus 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.

Tacrolimus belongs to Miscellaneous; Toremifene belongs to Endocrine.

Evidence level: Moderate

Why it happens

Additive prolongation of cardiac repolarisation (QT interval).

What to do

Avoid the combination where possible. If it is necessary, obtain a baseline and follow-up ECG, correct potassium and magnesium, and monitor tacrolimus levels.

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 Tacrolimus with Toremifene?

MediHelp rates the interaction as major. Tacrolimus 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. Both drugs can prolong the QT interval, so combined use raises the risk of torsades de pointes and other serious ventricular arrhythmias. The risk increases with electrolyte disturbances, bradycardia or underlying heart disease.

How serious is the interaction between Tacrolimus 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 where possible. If it is necessary, obtain a baseline and follow-up ECG, correct potassium and magnesium, and monitor tacrolimus levels.

What other medicines interact with Tacrolimus?

MediHelp also lists interactions of Tacrolimus with, for example, Adenovirus types 4 and 7 live, Bcg vaccine live, Cidofovir. The full list is on the Tacrolimus page.

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