Drug interactions
Cobicistat + Tamsulosin
Severity: Major
Cobicistat 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
Cobicistat is a strong CYP3A4 inhibitor and also inhibits CYP2D6, raising tamsulosin exposure. This may cause hypotension, dizziness and syncope.
What this interaction means in plain words
Cobicistat 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.
Cobicistat belongs to Miscellaneous; Tamsulosin belongs to Genitourinary.
Why it happens
Inhibition of CYP3A4 and CYP2D6 metabolism of tamsulosin.
What to do
Avoid the combination where possible and choose an alternative treatment. If used, monitor blood pressure and consider reducing tamsulosin.
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
- Doxazosin + Tamsulosin Major
- Idelalisib + Tamsulosin Major
Other interactions of Cobicistat
- Alfuzosin + Cobicistat Contraindicated
- Apalutamide + Cobicistat Contraindicated
- Cobicistat + Colchicine Contraindicated
- Cobicistat + Dronedarone Contraindicated
- Cobicistat + Eletriptan Contraindicated
- Cobicistat + Eplerenone Contraindicated
Frequently asked questions
Can I take Cobicistat with Tamsulosin?
MediHelp rates the interaction as major. Cobicistat 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. Cobicistat is a strong CYP3A4 inhibitor and also inhibits CYP2D6, raising tamsulosin exposure. This may cause hypotension, dizziness and syncope.
How serious is the interaction between Cobicistat 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 the combination where possible and choose an alternative treatment. If used, monitor blood pressure and consider reducing tamsulosin.
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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