Drug interactions
Sildenafil + Terazosin
Severity: Major
Sildenafil and Terazosin: 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 reduce blood pressure, and co-administration can result in symptomatic postural hypotension, dizziness or syncope, especially after the first doses.
What this interaction means in plain words
Sildenafil and Terazosin 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; Terazosin belongs to Genitourinary.
Why it happens
Additive vasodilation from PDE5 inhibition and alpha-1 adrenergic blockade.
What to do
Establish stable terazosin therapy before adding sildenafil at 25 mg, and avoid higher sildenafil doses within 4 hours of the alpha-blocker. Monitor blood pressure and counsel the patient on orthostatic symptoms.
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 Terazosin
- Alfuzosin + Terazosin Major
- Amifostine + Terazosin Major
- Avanafil + Terazosin Major
- Doxazosin + Terazosin Major
- Dutasteride-tamsulosin + Terazosin Major
- Lofexidine + Terazosin Major
Frequently asked questions
Can I take Sildenafil with Terazosin?
MediHelp rates the interaction as major. Sildenafil and Terazosin 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 reduce blood pressure, and co-administration can result in symptomatic postural hypotension, dizziness or syncope, especially after the first doses.
How serious is the interaction between Sildenafil and Terazosin?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Establish stable terazosin therapy before adding sildenafil at 25 mg, and avoid higher sildenafil doses within 4 hours of the alpha-blocker. Monitor blood pressure and counsel the patient on orthostatic symptoms.
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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