Drug interactions
Ethinylestradiol + Lapatinib
Severity: Minor
Ethinylestradiol 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
Ethinylestradiol is a weak CYP3A4 inhibitor, so a meaningful increase in lapatinib exposure is unlikely. Hormonal contraception may also be undesirable in hormone-sensitive cancer.
What this interaction means in plain words
Ethinylestradiol 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
Weak CYP3A4 inhibition by ethinylestradiol may slightly reduce lapatinib metabolism.
What to do
No dose adjustment is needed. Consider non-hormonal contraception during lapatinib therapy.
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 Ethinylestradiol with Lapatinib?
MediHelp rates the interaction as minor. Ethinylestradiol 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. Ethinylestradiol is a weak CYP3A4 inhibitor, so a meaningful increase in lapatinib exposure is unlikely. Hormonal contraception may also be undesirable in hormone-sensitive cancer.
How serious is the interaction between Ethinylestradiol 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 dose adjustment is needed. Consider non-hormonal contraception during lapatinib therapy.
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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