What the FDA labels say about taking them together
Elbasvir/grazoprevir and warfarin
Elbasvir/grazoprevir's FDA label of March 13, 2026 names warfarin in its drug interactions section; the warfarin label PlainMeds reads does not name elbasvir/grazoprevir. The elbasvir/grazoprevir label: “Frequent monitoring of relevant laboratory parameters or drug concentrations of concomitant medications such as CYP450 substrates with a narrow therapeutic index is recommended to ensure safe and effective use.”
Check it at the source: the elbasvir/grazoprevir FDA label on DailyMed (effective March 13, 2026, Merck Sharp & Dohme LLC); the warfarin FDA label on DailyMed (effective May 29, 2026, Amneal Pharmaceuticals LLC).
What does the elbasvir/grazoprevir label say about warfarin?
Elbasvir/grazoprevir label, drug interactionsFrequent monitoring of relevant laboratory parameters (e.g., International Normalized Ratio [INR] in patients taking warfarin, blood glucose levels in diabetic patients) or drug concentrations of concomitant medications such as CYP450 substrates with a narrow therapeutic index (e.g., certain immunosuppressants) is recommended to ensure safe and effective use.
Source: FDA drug label (ZEPATIER), Merck Sharp & Dohme LLC, effective March 13, 2026 (SPL set 164dc02a-9180-426a-b8b5-04ab39d2bbd4), via openFDA; the full label on DailyMed
What does the warfarin label say about elbasvir/grazoprevir?
Warfarin's label (effective May 29, 2026) does not name elbasvir/grazoprevir in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Warfarin Sodium), Amneal Pharmaceuticals LLC, effective May 29, 2026 (SPL set 558b7a0d-5490-4c1b-802e-3ab3f1efe760), 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
| Elbasvir/grazoprevir | Warfarin | |
|---|---|---|
| Labeled for | Hepatitis C | Blood clots (DVT and PE), Atrial fibrillation |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | n/a | $0.093 per tablet 2 mg tablet |
| Shortage now | A presentation being discontinued | No current entry |
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