What the FDA labels say about taking them together
Ensitrelvir and rifampin
Ensitrelvir's FDA label of June 3, 2026 names rifampin in its drug interactions section; the rifampin label PlainMeds reads does not name ensitrelvir. The ensitrelvir label: “Co-administration is contraindicated due to potential loss of virologic response.”
Check it at the source: the ensitrelvir FDA label on DailyMed (effective June 3, 2026, Shionogi Inc.); the rifampin FDA label on DailyMed (effective February 11, 2026, Lupin Pharmaceuticals, Inc.).
What does the ensitrelvir label say about rifampin?
Ensitrelvir label, drug interactionsDrug Class: Antimycobacterials; Drug (s) within Class: rifampin; Effect on Drug Concentration: ↓ ensitrelvir; Clinical Comment: Co-administration is contraindicated due to potential loss of virologic response.
Source: FDA drug label (XOCOVA), Shionogi Inc., effective June 3, 2026 (SPL set 526acf60-abc3-2cc2-e063-6294a90affa6), via openFDA; the full label on DailyMed
What does the rifampin label say about ensitrelvir?
Rifampin's label (effective February 11, 2026) does not name ensitrelvir in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (rifampin), Lupin Pharmaceuticals, Inc., effective February 11, 2026 (SPL set b56004f0-f23d-47f6-80c7-39884fccbccc), 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
| Ensitrelvir | Rifampin | |
|---|---|---|
| Labeled for | COVID-19 | n/a |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | n/a | $0.679 per capsule 300 mg capsule |
| 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