Drug interactions
Fluvoxamine + Lapatinib
Severity: Moderate
Fluvoxamine 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
Both drugs have been associated with QT prolongation, so combination may add to the risk of arrhythmia. Fluvoxamine's weak CYP3A4 inhibition could also modestly raise lapatinib exposure.
What this interaction means in plain words
Fluvoxamine 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.
Fluvoxamine belongs to Central Nervous System; Lapatinib belongs to Oncology.
Why it happens
Additive QT prolongation, with possible minor CYP3A4 inhibition raising lapatinib levels.
What to do
Check a baseline ECG and electrolytes, and repeat the ECG during therapy. Consider an alternative antidepressant with less QT effect if the 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 Fluvoxamine
- Agomelatine + Fluvoxamine Contraindicated
- Alosetron + Fluvoxamine Contraindicated
- Fezolinetant + Fluvoxamine Contraindicated
- Fluvoxamine + Isocarboxazid Contraindicated
- Fluvoxamine + Mavacamten Contraindicated
- Fluvoxamine + Methylene blue 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 Fluvoxamine with Lapatinib?
MediHelp rates the interaction as moderate. Fluvoxamine 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. Both drugs have been associated with QT prolongation, so combination may add to the risk of arrhythmia. Fluvoxamine's weak CYP3A4 inhibition could also modestly raise lapatinib exposure.
How serious is the interaction between Fluvoxamine 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: Check a baseline ECG and electrolytes, and repeat the ECG during therapy. Consider an alternative antidepressant with less QT effect if the QTc lengthens.
What other medicines interact with Fluvoxamine?
MediHelp also lists interactions of Fluvoxamine with, for example, Agomelatine, Alosetron, Fezolinetant. The full list is on the Fluvoxamine page.
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