What the FDA labels say about taking them together
Andexanet alfa and heparin
Andexanet alfa's FDA label of May 23, 2025 names heparin in its drug interactions section, and heparin's label names andexanet alfa too. The heparin label: “Andexanet alfa may reduce the efficacy of heparin when used concomitantly”
Check it at the source: the andexanet alfa FDA label on DailyMed (effective May 23, 2025); the heparin FDA label on DailyMed (effective November 28, 2025, Fresenius Kabi USA, LLC).
What does the andexanet alfa label say about heparin?
Andexanet alfa label, drug interactionsDRUG INTERACTIONS Do not use unfractionated heparin following ANDEXXA administration due to unresponsiveness characterized by non-prolongation of activated clotting times ( 7.1 ).
Andexanet alfa label, warnings and precautionsUnresponsiveness to unfractionated heparin leading to non-prolongation of activated clotting times and serious thrombotic events has occurred following ANDEXXA administration. [ see Postmarketing Experience (6.2) ].
Source: FDA drug label (ANDEXXA), AstraZeneca Pharmaceuticals LP, effective May 23, 2025 (SPL set 2d9d90a6-63e6-46ef-96ff-dd6519ae7b6c), via openFDA; the full label on DailyMed
What does the heparin label say about andexanet alfa?
Heparin Sodium label (Hospira, Inc., May 12, 2026), drug interactionsAndexanet alfa may reduce the efficacy of heparin when used concomitantly
Heparin Sodium label (Hospira, Inc., May 12, 2026), warnings and precautionsHeparin with Concomitant Use With Andexanet Alfa Unresponsiveness to unfractionated heparin leading to non-prolongation of activated clotting times and serious thrombotic events has occurred when unfractionated heparin was administered after use of andexanet alfa for the reversal of direct Factor Xa inhibitors (apixaban and rivaroxaban).
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
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
| Andexanet alfa | Heparin | |
|---|---|---|
| Labeled for | n/a | 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