Drug interactions
Formoterol + Promazine
Severity: Moderate
Formoterol 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
Promazine, a phenothiazine antipsychotic, can prolong the QT interval. Formoterol may add to this and lower potassium, increasing the risk of ventricular arrhythmia.
What this interaction means in plain words
Formoterol 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 QT prolongation (pharmacodynamic), with beta-2 agonist induced hypokalemia.
What to do
Check baseline ECG and electrolytes in patients with cardiac risk factors, and correct potassium. Consider an alternative if QTc is prolonged.
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 Formoterol
- Adagrasib + Formoterol Major
- Amiodarone + Formoterol Major
- Amisulpride + Formoterol Major
- Amitriptyline + Formoterol Major
- Amoxapine + Formoterol Major
- Arformoterol + Formoterol Major
Frequently asked questions
Can I take Formoterol with Promazine?
MediHelp rates the interaction as moderate. Formoterol 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. Promazine, a phenothiazine antipsychotic, can prolong the QT interval. Formoterol may add to this and lower potassium, increasing the risk of ventricular arrhythmia.
How serious is the interaction between Formoterol 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: Check baseline ECG and electrolytes in patients with cardiac risk factors, and correct potassium. Consider an alternative if QTc is prolonged.
What other medicines interact with Formoterol?
MediHelp also lists interactions of Formoterol with, for example, Adagrasib, Amiodarone, Amisulpride. The full list is on the Formoterol page.
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