Drug interactions
Formoterol + Perphenazine
Severity: Moderate
Formoterol and Perphenazine: 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
Perphenazine may prolong the QT interval, and formoterol can add to this and lower potassium. The combination may increase the risk of ventricular arrhythmia in susceptible patients.
What this interaction means in plain words
Formoterol and Perphenazine 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.
Formoterol belongs to Respiratory; Perphenazine belongs to Central Nervous System.
Why it happens
Additive QT prolongation, with beta-agonist related hypokalemia.
What to do
Monitor ECG and potassium in patients with cardiac risk factors or other QT-prolonging drugs. Correct electrolyte abnormalities and reassess if QTc lengthens.
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
Other interactions of Perphenazine
- Ibutilide + Perphenazine Contraindicated
- Perphenazine + Pimozide Contraindicated
- Perphenazine + Thioridazine Contraindicated
- Adagrasib + Perphenazine Major
- Alfentanil + Perphenazine Major
- Amiodarone + Perphenazine Major
Frequently asked questions
Can I take Formoterol with Perphenazine?
MediHelp rates the interaction as moderate. Formoterol and Perphenazine 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. Perphenazine may prolong the QT interval, and formoterol can add to this and lower potassium. The combination may increase the risk of ventricular arrhythmia in susceptible patients.
How serious is the interaction between Formoterol and Perphenazine?
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 potassium in patients with cardiac risk factors or other QT-prolonging drugs. Correct electrolyte abnormalities and reassess if QTc lengthens.
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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