Drug interactions
Nitroglycerin po + Sildenafil
Severity: Contraindicated
Nitroglycerin po 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
Phosphodiesterase-5 inhibitors greatly amplify the vasodilating effect of organic nitrates. Together they can cause profound, potentially fatal hypotension and myocardial ischemia.
What this interaction means in plain words
Nitroglycerin po 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
Nitrates raise cGMP through nitric oxide release while sildenafil blocks cGMP breakdown, causing excessive vasodilation.
What to do
Do not co-administer; nitrates should not be given within 24 hours of sildenafil. If a nitrate is needed urgently, use only under close hemodynamic monitoring and consider non-nitrate options.
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 po with Sildenafil?
MediHelp rates the interaction as contraindicated. Nitroglycerin po 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. Phosphodiesterase-5 inhibitors greatly amplify the vasodilating effect of organic nitrates. Together they can cause profound, potentially fatal hypotension and myocardial ischemia.
How serious is the interaction between Nitroglycerin po 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: Do not co-administer; nitrates should not be given within 24 hours of sildenafil. If a nitrate is needed urgently, use only under close hemodynamic monitoring and consider non-nitrate options.
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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