Nitroglycerin and Sildenafil Interaction
Drug interaction information between Nitroglycerin and Sildenafil.
Nitroglycerin and Sildenafil have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Nitroglycerin and Sildenafil. Major interactions are generally avoided, moderate ones may need monitoring or a dose adjustment, and minor ones are usually low-risk. This page shows the documented mechanism and guidance. Label-documented interactions are not a complete safety review, so always confirm your own medications with a pharmacist or doctor. Educational information, not medical advice.
How They Interact
Both of these drugs work to relax and widen your blood vessels. Taking them together can cause your blood pressure to drop to a dangerously low level.
What To Do
You should avoid taking these two medications together because the combination can be very dangerous for your heart and blood pressure.
FDA Label Information
PDE-5-Inhibitors such as avanafil, sildenafil, vardenafil, and tadalafil have been shown to potentiate the hypotensive effects of organic nitrates.
Nitroglycerin Also Interacts With
- Dapsone Topical moderate
- Lidocaine Topical moderate
- Aspirin minor
- Tadalafil minor
- Heparin minor
Sildenafil Also Interacts With
- Ketoconazole major
- Erythromycin major
- Itraconazole major
- Darunavir major
- Hydralazine/Isosorbide Dinitrate major
Frequently Asked Questions
Can I take Nitroglycerin and Sildenafil together?
This is a minor interaction. You should avoid taking these two medications together because the combination can be very dangerous for your heart and blood pressure.
How serious is the interaction between Nitroglycerin and Sildenafil?
This interaction is classified as "minor" severity by the FDA. Minor interactions are unlikely to cause significant problems but should still be mentioned to your healthcare provider.
Why do Nitroglycerin and Sildenafil interact?
Both of these drugs work to relax and widen your blood vessels. Taking them together can cause your blood pressure to drop to a dangerously low level.
Understanding the Nitroglycerin and Sildenafil Interaction
FDA-approved prescribing information for these two drugs flags their combination as a minor-severity interaction. Nitroglycerin belongs to the Nitrate Vasodilator class and Sildenafil belongs to the PDE5 Inhibitor class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Both of these drugs work to relax and widen your blood vessels. Severity tiers matter: major flags generally advise avoidance, moderate flags often require monitoring or dose adjustment, and minor flags may only call for awareness.
Context around a specific patient determines real-world impact. Nitroglycerin has 8 total documented interactions on file in this dataset, and Sildenafil has 10. Each additional medication compounds the interaction surface, which is why pharmacists run full-profile checks rather than evaluating one pair at a time. FDA-derived guidance for this pair is: You should avoid taking these two medications together because the combination can be very dangerous for your heart and blood pressure. Timing of doses, renal and hepatic function, age, and other concurrent prescriptions all shape whether a labeled interaction matters clinically.
An interaction flag is not a verdict. A large share of labeled interactions are managed routinely in clinical practice, the fix may be as simple as spacing doses or adding a monitoring test. Others require the prescriber to choose a different medication entirely. This page surfaces FDA-sourced labeling and openFDA data for educational purposes only; it is not medical advice and cannot account for your full clinical picture. Never start, stop, or adjust either Nitroglycerin or Sildenafil based on a web page, speak with your prescriber or pharmacist before making any change.
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. Always consult your healthcare provider about drug interactions.
Read our methodology - how this data is sourced, computed, and verified.