What the FDA labels say about taking them together
Dalteparin and heparin
Dalteparin's FDA label of September 30, 2025 names heparin in its contraindications section; heparin's label does not name dalteparin itself but warns about its class (anti-coagulants).
Check it at the source: the dalteparin FDA label on DailyMed (effective September 30, 2025, Pfizer Laboratories Div Pfizer Inc); the heparin FDA label on DailyMed (effective November 28, 2025, Fresenius Kabi USA, LLC).
What does the dalteparin label say about heparin?
Dalteparin label, contraindicationsPatients with a history of heparin induced thrombocytopenia or heparin induced thrombocytopenia with thrombosis.
Source: FDA drug label (Fragmin), Pfizer Laboratories Div Pfizer Inc, effective September 30, 2025 (SPL set 23527b8b-9b28-4e6d-9751-33b143975ac7), via openFDA; the full label on DailyMed
What does the heparin label say about dalteparin?
Heparin's label does not name dalteparin itself; it warns about its class (anti-coagulants):
Heparin label, warnings and precautionsAdrenal hemorrhage (with resultant acute adrenal insufficiency), ovarian hemorrhage, and retroperitoneal hemorrhage have occurred during anticoagulant therapy with heparin [see Adverse Reactions ( 6.1 )].
Heparin label, drug interactionsTo reduce the risk of bleeding, a reduction in the dose of antiplatelet agent or heparin is recommended. Other Interactions Digitalis, tetracyclines, nicotine or antihistamines may partially counteract the anticoagulant action of heparin sodium.
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
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
| Dalteparin | Heparin | |
|---|---|---|
| Labeled for | Angina, Heart attack and coronary artery disease, Blood clots (DVT and PE) | Blood clots (DVT and PE), Atrial fibrillation |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | n/a | $1.18 per mL 5,000 unit/mL vial |
| Shortage now | No current entry | In shortage |
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