Drug interactions
Lapatinib + Paroxetine
Severity: Moderate
Lapatinib and Paroxetine: 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 paroxetine may add slightly. Risk of arrhythmia increases with electrolyte disturbance or other QT-prolonging drugs.
What this interaction means in plain words
Lapatinib and Paroxetine 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 belongs to Oncology; Paroxetine belongs to Central Nervous System.
Why it happens
Additive effects on cardiac repolarization.
What to do
Correct hypokalemia and hypomagnesemia and obtain a baseline ECG. Monitor the QT interval during co-therapy.
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 Paroxetine
- Isocarboxazid + Paroxetine Contraindicated
- Methylene blue + Paroxetine Contraindicated
- Paroxetine + Phenelzine Contraindicated
- Paroxetine + Pimozide Contraindicated
- Paroxetine + Procarbazine Contraindicated
- Paroxetine + Selegiline Contraindicated
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 Lapatinib with Paroxetine?
MediHelp rates the interaction as moderate. Lapatinib and Paroxetine 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 paroxetine may add slightly. Risk of arrhythmia increases with electrolyte disturbance or other QT-prolonging drugs.
How serious is the interaction between Lapatinib and Paroxetine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Correct hypokalemia and hypomagnesemia and obtain a baseline ECG. Monitor the QT interval during co-therapy.
What other medicines interact with Paroxetine?
MediHelp also lists interactions of Paroxetine with, for example, Isocarboxazid, Methylene blue, Phenelzine. The full list is on the Paroxetine page.
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