Drug interactions
Lapatinib + Venlafaxine
Severity: Moderate
Lapatinib and Venlafaxine: 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 is associated with QT prolongation, and venlafaxine may contribute a small additional effect. The combined risk of arrhythmia is higher in patients with electrolyte disturbances or cardiac disease.
What this interaction means in plain words
Lapatinib and Venlafaxine 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; Venlafaxine belongs to Central Nervous System.
Why it happens
Additive QT interval prolongation.
What to do
Obtain a baseline ECG and correct potassium and magnesium before starting. Repeat ECG monitoring during treatment, especially after dose changes.
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 Venlafaxine
- Isocarboxazid + Venlafaxine Contraindicated
- Methylene blue + Venlafaxine Contraindicated
- Phenelzine + Venlafaxine Contraindicated
- Procarbazine + Venlafaxine Contraindicated
- Rasagiline + Venlafaxine Contraindicated
- Safinamide + Venlafaxine 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 Venlafaxine?
MediHelp rates the interaction as moderate. Lapatinib and Venlafaxine 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 is associated with QT prolongation, and venlafaxine may contribute a small additional effect. The combined risk of arrhythmia is higher in patients with electrolyte disturbances or cardiac disease.
How serious is the interaction between Lapatinib and Venlafaxine?
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 and correct potassium and magnesium before starting. Repeat ECG monitoring during treatment, especially after dose changes.
What other medicines interact with Venlafaxine?
MediHelp also lists interactions of Venlafaxine with, for example, Isocarboxazid, Methylene blue, Phenelzine. The full list is on the Venlafaxine page.
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