Drug interactions
Quinidine + Tamsulosin
Severity: Moderate
Quinidine 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
Quinidine inhibits CYP2D6 and CYP3A4, both of which metabolize tamsulosin, and may raise its levels. This may increase hypotension and dizziness.
What this interaction means in plain words
Quinidine 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.
Quinidine belongs to Anti Parasitic; Tamsulosin belongs to Genitourinary.
Why it happens
Quinidine inhibits CYP2D6 and CYP3A4 metabolism of tamsulosin.
What to do
Monitor blood pressure and orthostatic symptoms when starting quinidine. Reduce or stop tamsulosin if symptomatic 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 Quinidine
- Adagrasib + Quinidine Contraindicated
- Arsenic trioxide + Quinidine Contraindicated
- Artemether / lumefantrine + Quinidine Contraindicated
- Chloroquine + Quinidine Contraindicated
- Dofetilide + Quinidine Contraindicated
- Dronedarone + Quinidine Contraindicated
Frequently asked questions
Can I take Quinidine with Tamsulosin?
MediHelp rates the interaction as moderate. Quinidine 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. Quinidine inhibits CYP2D6 and CYP3A4, both of which metabolize tamsulosin, and may raise its levels. This may increase hypotension and dizziness.
How serious is the interaction between Quinidine 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 when starting quinidine. Reduce or stop tamsulosin if symptomatic 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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