Drug interactions
Asenapine + Promethazine
Severity: Major
Asenapine and Promethazine: 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
Co-administration of promethazine and asenapine may lead to a significant reduction in the QTc interval, potentially increasing the risk of cardiac arrhythmias. This interaction necessitates careful consideration due to the overlapping effects on cardiac conduction.
What this interaction means in plain words
Asenapine and Promethazine 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.
Asenapine belongs to Central Nervous System; Promethazine belongs to Respiratory.
Why it happens
Both drugs are known to influence cardiac repolarization, which can affect the QT interval. The exact pharmacological interactions leading to this effect are not fully elucidated.
What to do
Patients receiving both medications should be monitored closely for any signs of cardiac irregularities. Consider alternative therapies to minimize the risk of adverse cardiac events.
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 Promethazine
- Cabergoline + Promethazine Contraindicated
- Dopamine + Promethazine Contraindicated
- Ibutilide + Promethazine Contraindicated
- Pimozide + Promethazine Contraindicated
- Promethazine + Thioridazine Contraindicated
- Alfentanil + Promethazine Major
Other interactions of Asenapine
- Asenapine + Pimozide Contraindicated
- Asenapine + Thioridazine Contraindicated
- Asenapine + Vandetanib Contraindicated
- Adagrasib + Asenapine Major
- Alfentanil + Asenapine Major
- Alfuzosin + Asenapine Major
Frequently asked questions
Can I take Asenapine with Promethazine?
MediHelp rates the interaction as major. Asenapine and Promethazine 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. Co-administration of promethazine and asenapine may lead to a significant reduction in the QTc interval, potentially increasing the risk of cardiac arrhythmias. This interaction necessitates careful consideration due to the overlapping effects on cardiac conduction.
How serious is the interaction between Asenapine and Promethazine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Patients receiving both medications should be monitored closely for any signs of cardiac irregularities. Consider alternative therapies to minimize the risk of adverse cardiac events.
What other medicines interact with Promethazine?
MediHelp also lists interactions of Promethazine with, for example, Cabergoline, Dopamine, Ibutilide. The full list is on the Promethazine page.
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