Drug interactions
Protriptyline + Ziprasidone
Severity: Major
Protriptyline and Ziprasidone: major interaction.
Last updated Sources: US FDA label
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
Tricyclic antidepressants such as protriptyline can prolong the QT interval and cause conduction abnormalities. With ziprasidone, the risk of torsades de pointes and serious arrhythmia is increased.
What this interaction means in plain words
Protriptyline and Ziprasidone 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 hERG channel blockade and delayed repolarization.
What to do
Avoid the combination and consider a non-QT-prolonging antidepressant. If unavoidable, obtain a baseline ECG, monitor QTc and keep potassium and magnesium normal.
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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References
Other interactions of Ziprasidone
- Amiodarone + Ziprasidone Contraindicated
- Amitriptyline + Ziprasidone Contraindicated
- Arsenic trioxide + Ziprasidone Contraindicated
- Bedaquiline + Ziprasidone Contraindicated
- Chloroquine + Ziprasidone Contraindicated
- Citalopram + Ziprasidone Contraindicated
Frequently asked questions
Can I take Protriptyline with Ziprasidone?
MediHelp rates the interaction as major. Protriptyline and Ziprasidone 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. Tricyclic antidepressants such as protriptyline can prolong the QT interval and cause conduction abnormalities. With ziprasidone, the risk of torsades de pointes and serious arrhythmia is increased.
How serious is the interaction between Protriptyline and Ziprasidone?
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 and consider a non-QT-prolonging antidepressant. If unavoidable, obtain a baseline ECG, monitor QTc and keep potassium and magnesium normal.
What other medicines interact with Ziprasidone?
MediHelp also lists interactions of Ziprasidone with, for example, Amiodarone, Amitriptyline, Arsenic trioxide. The full list is on the Ziprasidone page.
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