Drug interactions
Pentamidine + Thioridazine
Severity: Contraindicated
Pentamidine and Thioridazine: contraindicated 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 prolong the QT interval, and pentamidine has been linked to torsades de pointes. The combination markedly raises arrhythmia risk.
What this interaction means in plain words
Pentamidine and Thioridazine are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.
Pentamidine belongs to Anti Parasitic; Thioridazine belongs to Central Nervous System.
Why it happens
Additive QT prolongation through blockade of cardiac potassium channels.
What to do
Avoid the combination and consider an alternative antipsychotic or anti-infective. If pentamidine is essential, stop thioridazine and monitor the ECG and electrolytes.
What to ask your pharmacist
- Is there an alternative to one of these two medicines for me?
- If both are essential, who is monitoring me and how often?
- Which symptoms mean I should stop and seek help straight away?
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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
Other interactions of Pentamidine
- Clomipramine + Pentamidine Contraindicated
- Desipramine + Pentamidine Contraindicated
- Dronedarone + Pentamidine Contraindicated
- Moxifloxacin + Pentamidine Contraindicated
- Nortriptyline + Pentamidine Contraindicated
- Pentamidine + Pimozide Contraindicated
Frequently asked questions
Can I take Pentamidine with Thioridazine?
MediHelp rates the interaction as contraindicated. Pentamidine and Thioridazine are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. Both drugs prolong the QT interval, and pentamidine has been linked to torsades de pointes. The combination markedly raises arrhythmia risk.
How serious is the interaction between Pentamidine and Thioridazine?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination and consider an alternative antipsychotic or anti-infective. If pentamidine is essential, stop thioridazine and monitor the ECG and electrolytes.
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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