Drug interactions
Estrogens conjugated synthetic + Lapatinib
Severity: Minor
Estrogens conjugated synthetic and Lapatinib: minor 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 inhibits CYP3A4 and P-glycoprotein, which may modestly increase estrogen exposure. This could increase estrogen-related adverse effects.
What this interaction means in plain words
Estrogens conjugated synthetic and Lapatinib have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Lapatinib inhibits CYP3A4 and P-glycoprotein, reducing estrogen clearance.
What to do
No routine adjustment is needed. Monitor for estrogenic adverse effects and reduce the estrogen dose if needed.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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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 Estrogens conjugated synthetic with Lapatinib?
MediHelp rates the interaction as minor. Estrogens conjugated synthetic and Lapatinib have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Lapatinib inhibits CYP3A4 and P-glycoprotein, which may modestly increase estrogen exposure. This could increase estrogen-related adverse effects.
How serious is the interaction between Estrogens conjugated synthetic and Lapatinib?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No routine adjustment is needed. Monitor for estrogenic adverse effects and reduce the estrogen dose if needed.
What other medicines interact with Lapatinib?
MediHelp also lists interactions of Lapatinib with, for example, Dofetilide, Ibutilide, Pimozide. The full list is on the Lapatinib page.
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