Drug interactions
Ketoconazole + Tamsulosin
Severity: Major
Ketoconazole and Tamsulosin: major 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
Ketoconazole strongly inhibits CYP3A4 and markedly raises tamsulosin exposure in pharmacokinetic studies. This increases the risk of symptomatic hypotension and syncope.
What this interaction means in plain words
Ketoconazole and Tamsulosin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Ketoconazole belongs to Anti Fungals; Tamsulosin belongs to Genitourinary.
Why it happens
Ketoconazole inhibits CYP3A4 and reduces tamsulosin first-pass and systemic clearance.
What to do
Avoid concurrent use; consider an alternative antifungal or hold tamsulosin during treatment. If unavoidable, monitor blood pressure and orthostatic symptoms closely.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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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 Ketoconazole
- Alfuzosin + Ketoconazole Contraindicated
- Alprazolam + Ketoconazole Contraindicated
- Avanafil + Ketoconazole Contraindicated
- Conivaptan + Ketoconazole Contraindicated
- Dihydroergotamine intranasal + Ketoconazole Contraindicated
- Dihydroergotamine + Ketoconazole Contraindicated
Frequently asked questions
Can I take Ketoconazole with Tamsulosin?
MediHelp rates the interaction as major. Ketoconazole and Tamsulosin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Ketoconazole strongly inhibits CYP3A4 and markedly raises tamsulosin exposure in pharmacokinetic studies. This increases the risk of symptomatic hypotension and syncope.
How serious is the interaction between Ketoconazole and Tamsulosin?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid concurrent use; consider an alternative antifungal or hold tamsulosin during treatment. If unavoidable, monitor blood pressure and orthostatic symptoms closely.
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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