Drug interactions
Gemtuzumab + Thioridazine
Severity: Major
Gemtuzumab and Thioridazine: 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 agents can prolong the QT interval, so giving them together raises the risk of torsades de pointes and other ventricular arrhythmias. Thioridazine carries a particularly high intrinsic QT liability, which makes this combination more concerning.
What this interaction means in plain words
Gemtuzumab and Thioridazine 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.
Why it happens
Additive prolongation of cardiac repolarization through pharmacodynamic synergism.
What to do
Avoid the combination where an alternative antipsychotic is possible; otherwise obtain a baseline and follow-up ECG and correct potassium and magnesium before and during treatment.
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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Other interactions of Thioridazine
- Abiraterone + Thioridazine Contraindicated
- Adagrasib + Thioridazine Contraindicated
- Amiodarone + Thioridazine Contraindicated
- Amisulpride + Thioridazine Contraindicated
- Amitriptyline + Thioridazine Contraindicated
- Amoxapine + Thioridazine Contraindicated
Frequently asked questions
Can I take Gemtuzumab with Thioridazine?
MediHelp rates the interaction as major. Gemtuzumab and Thioridazine 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 agents can prolong the QT interval, so giving them together raises the risk of torsades de pointes and other ventricular arrhythmias. Thioridazine carries a particularly high intrinsic QT liability, which makes this combination more concerning.
How serious is the interaction between Gemtuzumab and Thioridazine?
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 an alternative antipsychotic is possible; otherwise obtain a baseline and follow-up ECG and correct potassium and magnesium before and during treatment.
What other medicines interact with Thioridazine?
MediHelp also lists interactions of Thioridazine with, for example, Abiraterone, Adagrasib, Amiodarone. The full list is on the Thioridazine page.
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