Drug interactions
Sildenafil + Tamsulosin
Severity: Major
Sildenafil 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
Both drugs lower blood pressure through vasodilation, and together they can cause symptomatic orthostatic hypotension, dizziness or syncope. The risk is greatest on initiation or with higher sildenafil doses.
What this interaction means in plain words
Sildenafil 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.
Sildenafil belongs to Genitourinary; Tamsulosin belongs to Genitourinary.
Why it happens
Additive vasodilation from alpha-1 blockade and PDE5 inhibition.
What to do
Ensure the patient is stable on tamsulosin before starting sildenafil at the lowest dose (25 mg). Advise rising slowly and monitor 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 Sildenafil
- Amyl nitrite + Sildenafil Contraindicated
- Atazanavir + Sildenafil Contraindicated
- Cobicistat + Sildenafil Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Sildenafil Contraindicated
- Glyceryl trinitrate pr + Sildenafil Contraindicated
- Isosorbide dinitrate + Sildenafil Contraindicated
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 Sildenafil with Tamsulosin?
MediHelp rates the interaction as major. Sildenafil 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. Both drugs lower blood pressure through vasodilation, and together they can cause symptomatic orthostatic hypotension, dizziness or syncope. The risk is greatest on initiation or with higher sildenafil doses.
How serious is the interaction between Sildenafil 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: Ensure the patient is stable on tamsulosin before starting sildenafil at the lowest dose (25 mg). Advise rising slowly and monitor blood pressure.
What other medicines interact with Sildenafil?
MediHelp also lists interactions of Sildenafil with, for example, Amyl nitrite, Atazanavir, Cobicistat. The full list is on the Sildenafil page.
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