What the FDA labels say about taking them together
Heparin and nitroglycerin
Heparin's FDA label (Heparin Sodium) of April 30, 2026 names nitroglycerin in its drug interactions section, and nitroglycerin's label names heparin too. The nitroglycerin label: “… Tissue-type Plasminogen Activator (t-PA): decreased thrombolytic effect. Heparin: anticoagulant effect of heparin may be reduced.”
Check it at the source: the heparin FDA label on DailyMed (effective November 28, 2025, Fresenius Kabi USA, LLC); the nitroglycerin FDA label on DailyMed (effective February 15, 2023, Viatris Specialty LLC).
What does the heparin label say about nitroglycerin?
Heparin Sodium label (Fresenius Kabi USA, LLC, April 30, 2026), drug interactionsIntravenous nitroglycerin administered to heparinized patients may result in a decrease of the partial thromboplastin time with subsequent rebound effect upon discontinuation of nitroglycerin.
Heparin Sodium label (Hospira, Inc., May 12, 2026), drug interactionsOther Interactions Digitalis, tetracyclines, nicotine, or antihistamines, or intravenous nitroglycerin may partially counteract the anticoagulant action of heparin sodium.
Source: FDA drug label (Heparin Sodium, NDA017029), Fresenius Kabi USA, LLC, effective April 30, 2026 (SPL set 2a173253-dfdc-4d9d-8dee-b9c13e6fa9f5), via openFDA
Source: FDA drug label (Heparin Sodium, NDA018916), Hospira, Inc., effective May 12, 2026 (SPL set 0413f511-6b34-4c15-e48b-3fad08baacbe), via openFDA
Source: FDA drug label (Heparin Sodium), Fresenius Kabi USA, LLC, effective November 28, 2025 (SPL set d55b4a63-0c04-4874-b74f-9e9b9e8b008c), via openFDA; the full label on DailyMed
What does the nitroglycerin label say about heparin?
Nitroglycerin In Dextrose label (Baxter Healthcare Company, August 22, 2016), drug interactionsNitroglycerin at higher dosages may interfere with the anticoagulant effect of heparin.
Rectiv label (Allergan, Inc., September 8, 2026), drug interactionsDRUG INTERACTIONS PDE5 inhibitors: potentiation of hypotensive effects of organic nitrates; concomitant use is contraindicated. ( 4.1 , 7.1 ) Antihypertensives: possible additive hypotensive effects. ( 7.2 ) Aspirin: increased nitroglycerin levels. ( 7.3 ) Tissue-type Plasminogen Activator (t-PA): decreased thrombolytic effect. ( 7.4 ) Heparin: anticoagulant effect of heparin may be reduced.
Source: FDA drug label (Nitroglycerin In Dextrose, NDA019970), Baxter Healthcare Company, effective August 22, 2016 (SPL set 457a026c-ebce-4701-9deb-2d7652759a99), via openFDA
Source: FDA drug label (Rectiv, NDA021359), Allergan, Inc., effective September 8, 2026 (SPL set 603aa9ed-54c4-4a35-ade4-690fa44850e4), via openFDA
Source: FDA drug label (Nitrostat), Viatris Specialty LLC, effective February 15, 2023 (SPL set 9a52da75-d0af-4237-96c0-0b12adfa8636), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Heparin | Nitroglycerin | |
|---|---|---|
| Labeled for | Blood clots (DVT and PE), Atrial fibrillation | Angina, High blood pressure, Heart failure, Heart attack and coronary artery disease |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $1.18 per mL 5,000 unit/mL vial | $0.127 per tablet 0.4 mg tablet sl |
| Shortage now | In shortage | A presentation being discontinued |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once