Drug interactions
Promazine + Trazodone
Severity: Major
Promazine and Trazodone: 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
Promazine, a phenothiazine, and trazodone can each prolong the QT interval. Used together they may raise the risk of torsades de pointes, and additive sedation and hypotension may also occur.
What this interaction means in plain words
Promazine and Trazodone 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 QTc prolongation, with additive sedative and alpha-blocking effects.
What to do
Avoid the combination where possible. If both are needed, obtain a baseline ECG, correct electrolytes and monitor QTc and orthostatic blood pressure.
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 Trazodone
- Arsenic trioxide + Trazodone Contraindicated
- Ibutilide + Trazodone Contraindicated
- Isocarboxazid + Trazodone Contraindicated
- Levoketoconazole + Trazodone Contraindicated
- Methylene blue + Trazodone Contraindicated
- Phenelzine + Trazodone Contraindicated
Frequently asked questions
Can I take Promazine with Trazodone?
MediHelp rates the interaction as major. Promazine and Trazodone 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. Promazine, a phenothiazine, and trazodone can each prolong the QT interval. Used together they may raise the risk of torsades de pointes, and additive sedation and hypotension may also occur.
How serious is the interaction between Promazine and Trazodone?
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 both are needed, obtain a baseline ECG, correct electrolytes and monitor QTc and orthostatic blood pressure.
What other medicines interact with Trazodone?
MediHelp also lists interactions of Trazodone with, for example, Arsenic trioxide, Ibutilide, Isocarboxazid. The full list is on the Trazodone page.
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