Drug interactions
Formoterol + Lapatinib
Severity: Moderate
Formoterol and Lapatinib: 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
Lapatinib can prolong the QT interval, and formoterol may add QTc effects and lower potassium. The combination may increase arrhythmia risk, especially with electrolyte abnormalities or cardiac disease.
What this interaction means in plain words
Formoterol and Lapatinib 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; Lapatinib belongs to Oncology.
Why it happens
Additive QT prolongation, with beta2-agonist-induced hypokalemia.
What to do
Obtain a baseline ECG, correct potassium and magnesium, and repeat the ECG if symptoms occur or other QT-prolonging drugs are added.
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 Lapatinib
- Dofetilide + Lapatinib Contraindicated
- Ibutilide + Lapatinib Contraindicated
- Lapatinib + Pimozide Contraindicated
- Lapatinib + Saquinavir Contraindicated
- Lapatinib + Thioridazine Contraindicated
- Adagrasib + Lapatinib Major
Frequently asked questions
Can I take Formoterol with Lapatinib?
MediHelp rates the interaction as moderate. Formoterol and Lapatinib 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. Lapatinib can prolong the QT interval, and formoterol may add QTc effects and lower potassium. The combination may increase arrhythmia risk, especially with electrolyte abnormalities or cardiac disease.
How serious is the interaction between Formoterol and Lapatinib?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Obtain a baseline ECG, correct potassium and magnesium, and repeat the ECG if symptoms occur or other QT-prolonging drugs are added.
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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