Drug interactions
Conjugated estrogens vaginal + Lapatinib
Severity: Minor
Conjugated estrogens vaginal 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
Vaginal conjugated estrogens produce low systemic exposure, so any rise in estrogen levels from lapatinib is expected to be small. The clinical relevance is limited.
What this interaction means in plain words
Conjugated estrogens vaginal 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, which could slightly raise systemic estrogen levels.
What to do
No action is generally needed. Note that estrogen therapy may be undesirable in hormone-sensitive breast cancer and should be reviewed separately.
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 Conjugated estrogens vaginal with Lapatinib?
MediHelp rates the interaction as minor. Conjugated estrogens vaginal 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. Vaginal conjugated estrogens produce low systemic exposure, so any rise in estrogen levels from lapatinib is expected to be small. The clinical relevance is limited.
How serious is the interaction between Conjugated estrogens vaginal 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 action is generally needed. Note that estrogen therapy may be undesirable in hormone-sensitive breast cancer and should be reviewed separately.
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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