Drug interactions
Isoproterenol + Promazine
Severity: Moderate
Isoproterenol and Promazine: moderate 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
Isoproterenol is a potent beta-agonist that raises heart rate and can provoke arrhythmias. Promazine, a phenothiazine, can prolong the QT interval and cause alpha-blockade with vasodilation, so combined use may increase the risk of tachyarrhythmia and hypotension, particularly in predisposed patients.
What this interaction means in plain words
Isoproterenol and Promazine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Additive pharmacodynamic effects: beta-adrenergic chronotropy and arrhythmogenicity combined with phenothiazine QT prolongation and alpha-blockade-related vasodilation.
What to do
Monitor ECG and blood pressure when the two are given together, especially in patients with cardiac disease or electrolyte disturbances. Correct potassium and magnesium abnormalities beforehand.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Isoproterenol
Frequently asked questions
Can I take Isoproterenol with Promazine?
MediHelp rates the interaction as moderate. Isoproterenol and Promazine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Isoproterenol is a potent beta-agonist that raises heart rate and can provoke arrhythmias. Promazine, a phenothiazine, can prolong the QT interval and cause alpha-blockade with vasodilation, so combined use may increase the risk of tachyarrhythmia and hypotension, particularly in predisposed patients.
How serious is the interaction between Isoproterenol and Promazine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor ECG and blood pressure when the two are given together, especially in patients with cardiac disease or electrolyte disturbances. Correct potassium and magnesium abnormalities beforehand.
What other medicines interact with Isoproterenol?
MediHelp also lists interactions of Isoproterenol with, for example, Adrenaline-articaine, Bisoprolol, Budesonide-formoterol. The full list is on the Isoproterenol page.
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