What the FDA labels say about taking them together
Rifabutin and voriconazole
Rifabutin's FDA label of September 1, 2026 names voriconazole in its drug interactions section, and voriconazole's label names rifabutin too. The rifabutin label: “CONTRAINDICATED”
Check it at the source: the rifabutin FDA label on DailyMed (effective September 1, 2026, REMEDYREPACK INC.); the voriconazole FDA label on DailyMed (effective February 26, 2026, Roerig).
What does the rifabutin label say about voriconazole?
Rifabutin label, drug interactionsCo-administered drug: Voriconazole; Dosing regimen of co-administered drug: 400 mg twice a day for 7 days (maintenance dose); Dosing regimen of rifabutin: 300 mg once a day for 7 days; Study population (n): Healthy male subjects (12); Effect on rifabutin: ↑ AUC by 331%, ↑ C max by 195%; Effect on co-administered drug: ↑ AUC by ~100%, ↑ C max by ~100% compared to voriconazole 200 mg twice a day alone; Recommendation: CONTRAINDICATED
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
What does the voriconazole label say about rifabutin?
Voriconazole label, contraindicationsRifabutin [see Clinical Pharmacology (12.3) ]
Voriconazole label, drug interactionsDrug/Drug Class (Mechanism of Interaction by the Drug): Rifampin Results based on in vivo clinical studies generally following repeat oral dosing with 200 mg every 12 hours voriconazole to healthy subjects and Rifabutin (CYP450 Induction); Voriconazole Plasma Exposure (C max and AUC τ after 200 mg every 12 hours): Significantly Reduced; Prevention or Management Recommendations: Contraindicated
Voriconazole label (Xellia Pharmaceuticals USA LLC, January 11, 2023), contraindicationsCoadministration of Voriconazole for injection with rifabutin is contraindicated since Voriconazole for injection significantly increases rifabutin plasma concentrations and rifabutin also significantly decreases voriconazole plasma concentrations [see Drug Interactions (7) and Clinical Pharmacology (12.3) ].
Voriconazole label (Xellia Pharmaceuticals USA LLC, January 11, 2023), drug interactionsDrug/Drug Class (Mechanism of Interaction by the Drug): Rifampin and Rifabutin (CYP450 Induction); Voriconazole Plasma Exposure (C max and AUC τ after 200 mg every 12 hours): Significantly Reduced; Recommendations for Voriconazole Dosage Adjustment/Comments: Contraindicated
Source: FDA drug label (Voriconazole, NDA208562), Xellia Pharmaceuticals USA LLC, effective January 11, 2023 (SPL set 9ec6eda2-2f15-423b-9ec6-819379a426e1), via openFDA
Source: FDA drug label (VFEND), NDA021630 (Pf Prism Cv), as published by Roerig, effective February 26, 2026 (SPL set ce3ef5cf-3087-4d92-9d94-9eb8287228db), 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
| Rifabutin | Voriconazole | |
|---|---|---|
| Labeled for | n/a | Fungal infections |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $8.14 per capsule 150 mg capsule | $1.88 per tablet 200 mg tablet |
| Shortage now | No current entry | A presentation being discontinued |
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