Heparin and Nitroglycerin Interaction
Drug interaction information between Heparin and Nitroglycerin.
Heparin and Nitroglycerin have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Heparin and Nitroglycerin. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.
How They Interact
Nitroglycerin can make heparin less effective at thinning the blood, which changes how quickly the blood clots.
FDA Label Information
Intravenous nitroglycerin administered to heparinized patients may result in a decrease of the partial thromboplastin time with subsequent rebound effect upon discontinuation of nitroglycerin. Careful monitoring of partial thromboplastin time and adjustment of heparin dosage are recommended during coadministration of heparin and intravenous nitroglycerin.
Heparin Also Interacts With
- Ibuprofen moderate
- Celecoxib moderate
- Hydroxychloroquine moderate
- Indomethacin moderate
- Dipyridamole moderate
Nitroglycerin Also Interacts With
- Dapsone Topical moderate
- Lidocaine Topical moderate
- Aspirin minor
- Sildenafil minor
- Tadalafil minor
Frequently Asked Questions
What SPL severity band is on file for Heparin + Nitroglycerin?
Compiled FDA labeling labels this pair minor. That is a source-record field, not an individual medication-combination decision.
Which drug in this pair has the larger labeled-interaction portfolio?
Heparin has 20 labeled pairs on file vs Nitroglycerin's 8. In the minor band specifically: Heparin has 10 (also Amlodipine/Valsartan, Levothyroxine, Liothyronine, Oritavancin); Nitroglycerin has 6 (also Aspirin, Sildenafil, Tadalafil, Isradipine).
What mechanism field is on file for Heparin and Nitroglycerin?
Nitroglycerin can make heparin less effective at thinning the blood, which changes how quickly the blood clots.
Heparin's labeled portfolio outnumbers Nitroglycerin
SPL source-record counts only. This page's band is minor · classes on file: Heparin (Unfractionated Heparin); Nitroglycerin (Nitrate Vasodilator).
0 major · 10 moderate · 10 minor · 20 total
- Other minor peers for Heparin
- Amlodipine/Valsartan
- Levothyroxine
- Liothyronine
- Oritavancin
0 major · 2 moderate · 6 minor · 8 total
- Other minor peers for Nitroglycerin
- Aspirin
- Sildenafil
- Tadalafil
- Isradipine
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.
Read our methodology - how this data is sourced, computed, and verified.