Drug interactions
Tadalafil + Terazosin
Severity: Major
Tadalafil 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
Concurrent use of a PDE5 inhibitor with a non-selective alpha-1 blocker like terazosin can produce significant postural hypotension and syncope. The risk is greater at treatment initiation and with higher doses.
What this interaction means in plain words
Tadalafil 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.
Tadalafil belongs to Genitourinary; Terazosin belongs to Genitourinary.
Why it happens
Additive vasodilation from alpha-1 blockade and PDE5 inhibition.
What to do
Start tadalafil at the lowest dose only after the alpha-blocker dose is stable, and monitor orthostatic blood pressure. Separate the start of each drug and stop or reduce if symptomatic.
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 Tadalafil
- Amyl nitrite + Tadalafil Contraindicated
- Isosorbide dinitrate + Tadalafil Contraindicated
- Isosorbide mononitrate + Tadalafil Contraindicated
- Nitroglycerin po + Tadalafil Contraindicated
- Nitroglycerin rectal + Tadalafil Contraindicated
- Nitroglycerin sublingual + Tadalafil 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 Tadalafil with Terazosin?
MediHelp rates the interaction as major. Tadalafil 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. Concurrent use of a PDE5 inhibitor with a non-selective alpha-1 blocker like terazosin can produce significant postural hypotension and syncope. The risk is greater at treatment initiation and with higher doses.
How serious is the interaction between Tadalafil 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: Start tadalafil at the lowest dose only after the alpha-blocker dose is stable, and monitor orthostatic blood pressure. Separate the start of each drug and stop or reduce if symptomatic.
What other medicines interact with Tadalafil?
MediHelp also lists interactions of Tadalafil with, for example, Amyl nitrite, Isosorbide dinitrate, Isosorbide mononitrate. The full list is on the Tadalafil page.
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