Drug interactions
Nitroglycerin transdermal + Sildenafil
Severity: Contraindicated
Nitroglycerin transdermal and Sildenafil: 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
Transdermal nitroglycerin provides continuous nitrate exposure, and sildenafil can greatly enhance its vasodilating effect. Severe hypotension and cardiac ischemia may result.
What this interaction means in plain words
Nitroglycerin transdermal and Sildenafil 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
Additive increase in cGMP from nitric oxide donation and PDE5 inhibition causes excessive vasodilation.
What to do
Avoid combination; remove the patch and wait at least 24 hours before sildenafil where nitrate is not essential. Consider alternatives to either agent in patients needing both.
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 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
Frequently asked questions
Can I take Nitroglycerin transdermal with Sildenafil?
MediHelp rates the interaction as contraindicated. Nitroglycerin transdermal and Sildenafil 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. Transdermal nitroglycerin provides continuous nitrate exposure, and sildenafil can greatly enhance its vasodilating effect. Severe hypotension and cardiac ischemia may result.
How serious is the interaction between Nitroglycerin transdermal and Sildenafil?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid combination; remove the patch and wait at least 24 hours before sildenafil where nitrate is not essential. Consider alternatives to either agent in patients needing both.
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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