Drug interactions
Dosulepin + Promethazine
Severity: Major
Dosulepin 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
The concurrent use of promethazine and dosulepin can lead to an increased risk of QTc interval prolongation, which may result in serious cardiac arrhythmias. Patients taking both medications should be monitored closely for signs of cardiac issues due to this potential interaction.
What this interaction means in plain words
Dosulepin 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.
Dosulepin belongs to Central Nervous System; Promethazine belongs to Respiratory.
Why it happens
Both drugs are known to affect cardiac repolarization, leading to an extended QTc interval. This effect is likely due to their influence on cardiac ion channels.
What to do
It is advisable to avoid co-administration of these two medications whenever possible. If their concurrent use is necessary, patients should be monitored with regular ECG assessments to evaluate the QTc interval.
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 Dosulepin
- Dosulepin + Isocarboxazid Contraindicated
- Dosulepin + Phenelzine Contraindicated
- Dosulepin + Thioridazine Contraindicated
- Dosulepin + Tranylcypromine Contraindicated
- Amitriptyline + Dosulepin Major
- Buprenorphine + Dosulepin Major
Frequently asked questions
Can I take Dosulepin with Promethazine?
MediHelp rates the interaction as major. Dosulepin 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. The concurrent use of promethazine and dosulepin can lead to an increased risk of QTc interval prolongation, which may result in serious cardiac arrhythmias. Patients taking both medications should be monitored closely for signs of cardiac issues due to this potential interaction.
How serious is the interaction between Dosulepin 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: It is advisable to avoid co-administration of these two medications whenever possible. If their concurrent use is necessary, patients should be monitored with regular ECG assessments to evaluate the QTc interval.
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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