Drug interactions
Nitroglycerin po + Tadalafil
Severity: Contraindicated
Nitroglycerin po and Tadalafil: contraindicated 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
Tadalafil strongly potentiates nitrate-induced vasodilation, which can cause severe and possibly fatal hypotension. Its long half-life means the interaction persists for days.
What this interaction means in plain words
Nitroglycerin po and Tadalafil are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.
Why it happens
Nitrate-derived nitric oxide raises cGMP while tadalafil blocks PDE5 degradation, causing excessive vasodilation.
What to do
Do not co-administer; avoid nitrates for at least 48 hours after a tadalafil dose. Use non-nitrate options and monitor closely if a nitrate is needed urgently.
What to ask your pharmacist
- Is there an alternative to one of these two medicines for me?
- If both are essential, who is monitoring me and how often?
- Which symptoms mean I should stop and seek help straight away?
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Other interactions of Tadalafil
- Amyl nitrite + Tadalafil Contraindicated
- Isosorbide dinitrate + Tadalafil Contraindicated
- Isosorbide mononitrate + Tadalafil Contraindicated
- Nitroglycerin rectal + Tadalafil Contraindicated
- Nitroglycerin sublingual + Tadalafil Contraindicated
- Nitroglycerin transdermal + Tadalafil Contraindicated
Frequently asked questions
Can I take Nitroglycerin po with Tadalafil?
MediHelp rates the interaction as contraindicated. Nitroglycerin po and Tadalafil are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. Tadalafil strongly potentiates nitrate-induced vasodilation, which can cause severe and possibly fatal hypotension. Its long half-life means the interaction persists for days.
How serious is the interaction between Nitroglycerin po and Tadalafil?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Do not co-administer; avoid nitrates for at least 48 hours after a tadalafil dose. Use non-nitrate options and monitor closely if a nitrate is needed urgently.
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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