Drug interactions
Epinephrine racemic + Promethazine
Severity: Major
Epinephrine racemic 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 racemic epinephrine may lead to an increased risk of QTc interval prolongation, which can result in serious cardiac arrhythmias. Clinicians should be cautious when prescribing these medications together due to their potential additive effects on cardiac conduction.
What this interaction means in plain words
Epinephrine racemic 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.
Why it happens
Both drugs are known to influence cardiac repolarization, leading to a prolongation of the QTc interval, although the exact mechanism of their interaction is not fully understood.
What to do
It is advisable to monitor the QTc interval in patients receiving both medications. If significant prolongation is observed or if the patient has a history of cardiac issues, consider alternative treatment options.
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
Frequently asked questions
Can I take Epinephrine racemic with Promethazine?
MediHelp rates the interaction as major. Epinephrine racemic 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 racemic epinephrine may lead to an increased risk of QTc interval prolongation, which can result in serious cardiac arrhythmias. Clinicians should be cautious when prescribing these medications together due to their potential additive effects on cardiac conduction.
How serious is the interaction between Epinephrine racemic 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 monitor the QTc interval in patients receiving both medications. If significant prolongation is observed or if the patient has a history of cardiac issues, consider alternative treatment options.
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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