What the FDA labels say about taking them together
Emtricitabine and rifabutin
Rifabutin's FDA label of September 1, 2026 names emtricitabine in its drug interactions section; the emtricitabine label PlainMeds reads does not name rifabutin. The rifabutin label: “Co-administration of rifabutin with Biktarvy is not recommended due to an expected decrease in tenofovir alafenamide in addition to the reported reduction in bictegravir. …”
Check it at the source: the emtricitabine FDA label on DailyMed (effective December 2, 2025, Gilead Sciences, Inc.); the rifabutin FDA label on DailyMed (effective September 1, 2026, REMEDYREPACK INC.).
What does the emtricitabine label say about rifabutin?
Emtricitabine's label (effective December 2, 2025) does not name rifabutin in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Emtriva), Gilead Sciences, Inc., effective December 2, 2025 (SPL set d6599395-3944-44f9-97f2-e0424c6b6a1f), via openFDA; the full label on DailyMed
What does the rifabutin label say about emtricitabine?
Rifabutin label, drug interactionsCo-administered drug: Bictegravir; Dosing regimen of co-administered drug: 75 mg once a day; Dosing regimen of rifabutin: 300 mg once a day (fasted); Study population (n): Healthy subjects; Effect on rifabutin: ND; Effect on co-administered drug: ↓ AUC 38% ↓ C min 56% ↓ C max 20%; Recommendation: Co-administration of rifabutin with Biktarvy (bictegravir/emtricitabine/ tenofovir alafenamide) is not recommended due to an expected decrease in tenofovir alafenamide in addition to the reported reduction in bictegravir. Refer to Biktarvy prescribing information for additional information.
Source: FDA drug label (Rifabutin), NDA050689 (Pfizer), as published by REMEDYREPACK INC., effective September 1, 2026 (SPL set 25a60937-cbbe-4a50-994f-2ce15203f589), 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
| Emtricitabine | Rifabutin | |
|---|---|---|
| Labeled for | HIV | n/a |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $12.69 per capsule 200 mg capsule | $8.14 per capsule 150 mg capsule |
| 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