Drug interactions
Saquinavir + Tamsulosin
Severity: Major
Saquinavir 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
Saquinavir, usually ritonavir-boosted, inhibits CYP3A4 and can increase tamsulosin exposure. This may cause hypotension and syncope.
What this interaction means in plain words
Saquinavir 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.
Why it happens
Inhibition of CYP3A4 reduces tamsulosin clearance.
What to do
Avoid if possible; otherwise use the lowest tamsulosin dose and monitor orthostatic blood pressure.
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
Frequently asked questions
Can I take Saquinavir with Tamsulosin?
MediHelp rates the interaction as major. Saquinavir 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. Saquinavir, usually ritonavir-boosted, inhibits CYP3A4 and can increase tamsulosin exposure. This may cause hypotension and syncope.
How serious is the interaction between Saquinavir 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 if possible; otherwise use the lowest tamsulosin dose and monitor orthostatic blood pressure.
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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