What the FDA labels say about taking them together
Brincidofovir and rifampin
Brincidofovir's FDA label of July 1, 2025 names rifampin in its drug interactions section; the rifampin label PlainMeds reads does not name brincidofovir. The brincidofovir label: “Drugs on TEMBEXA Inhibitors for Organic Anion Transporting Polypeptide (OATP) 1B1 and 1B3 Concomitant use of TEMBEXA with OATP1B1 and 1B3 inhibitors increase brincidofovir AUC and C max which may increase …”
Check it at the source: the brincidofovir FDA label on DailyMed (effective July 1, 2025, Emergent BioDefense Operations Lansing LLC); the rifampin FDA label on DailyMed (effective February 11, 2026, Lupin Pharmaceuticals, Inc.).
What does the brincidofovir label say about rifampin?
Brincidofovir label, drug interactionsDrugs on TEMBEXA Inhibitors for Organic Anion Transporting Polypeptide (OATP) 1B1 and 1B3 Concomitant use of TEMBEXA with OATP1B1 and 1B3 inhibitors (clarithromycin, cyclosporine, erythromycin, gemfibrozil, human immunodeficiency virus [HIV] and hepatitis C virus [HCV] protease inhibitors, rifampin [single dose]) increase brincidofovir AUC and C max which may increase TEMBEXA-associated adverse reactions [see Clinical Pharmacology ( 12.3 )].
Source: FDA drug label (Tembexa), Emergent BioDefense Operations Lansing LLC, effective July 1, 2025 (SPL set 209aa94b-c613-4880-ad89-41be83d12c0a), via openFDA; the full label on DailyMed
What does the rifampin label say about brincidofovir?
Rifampin's label (effective February 11, 2026) does not name brincidofovir 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
| Brincidofovir | Rifampin | |
|---|---|---|
| Labeled for | n/a | n/a |
| Boxed warning | Yes | 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