Drug interactions
Lapatinib + Tamsulosin
Severity: Moderate
Lapatinib and Tamsulosin: 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 inhibits CYP3A4 and may increase tamsulosin exposure. Higher levels can produce dizziness and orthostatic hypotension.
What this interaction means in plain words
Lapatinib and Tamsulosin 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; Tamsulosin belongs to Genitourinary.
Why it happens
Lapatinib inhibits CYP3A4, reducing tamsulosin clearance.
What to do
Monitor blood pressure and orthostatic symptoms during lapatinib therapy. Reduce the tamsulosin dose if hypotension occurs.
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 Tamsulosin
- Alfuzosin + Tamsulosin Major
- Avanafil + Tamsulosin Major
- Ceritinib + Tamsulosin Major
- Clarithromycin + Tamsulosin Major
- Cobicistat + Tamsulosin Major
- Doxazosin + Tamsulosin Major
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 Tamsulosin?
MediHelp rates the interaction as moderate. Lapatinib and Tamsulosin 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 inhibits CYP3A4 and may increase tamsulosin exposure. Higher levels can produce dizziness and orthostatic hypotension.
How serious is the interaction between Lapatinib and Tamsulosin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor blood pressure and orthostatic symptoms during lapatinib therapy. Reduce the tamsulosin dose if hypotension occurs.
What other medicines interact with Tamsulosin?
MediHelp also lists interactions of Tamsulosin with, for example, Alfuzosin, Avanafil, Ceritinib. The full list is on the Tamsulosin page.
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