What the FDA labels say about taking them together
Ivacaftor and voriconazole
Ivacaftor's FDA label of March 23, 2026 names voriconazole in its drug interactions section, and voriconazole's label names ivacaftor too. The voriconazole label: “Dose reduction of ivacaftor is recommended. Refer to the prescribing information for ivacaftor.”
Check it at the source: the ivacaftor FDA label on DailyMed (effective March 23, 2026, Vertex Pharmaceuticals Incorporated); the voriconazole FDA label on DailyMed (effective February 26, 2026, Roerig).
What does the ivacaftor label say about voriconazole?
Ivacaftor label, drug interactionsBased on simulations of these results, a reduction of the KALYDECO dosage is recommended for patients aged 6 months and older taking concomitant strong CYP3A inhibitors, such as ketoconazole, itraconazole, posaconazole, voriconazole, telithromycin, and clarithromycin.
Source: FDA drug label (Kalydeco), Vertex Pharmaceuticals Incorporated, effective March 23, 2026 (SPL set 0ab0c9f8-3eee-4e0f-9f3f-c1e16aaffe25), via openFDA; the full label on DailyMed
What does the voriconazole label say about ivacaftor?
Voriconazole label, drug interactionsDrug/Drug Class (Mechanism of Interaction by Voriconazole): Ivacaftor (CYP3A4 Inhibition); Drug Plasma Exposure (C max and AUC τ): Not Studied In Vivo or In Vitro, but Drug Plasma Exposure Likely to be Increased which may Increase the Risk of Adverse Reactions; Prevention or Management Recommendations: Dose reduction of ivacaftor is recommended. Refer to the prescribing information for ivacaftor.
Voriconazole label (Xellia Pharmaceuticals USA LLC, January 11, 2023), drug interactionsDrug/Drug Class (Mechanism of Interaction by Voriconazole): Ivacaftor (CYP3A4 Inhibition); Drug Plasma Exposure (C max and AUC τ): Not Studied In Vivo or In Vitro, but Drug Plasma Exposure Likely to be Increased which may Increase the Risk of Adverse Reactions; Recommendations for Drug Dosage Adjustment/Comments: Dose reduction of ivacaftor is recommended. Refer to the prescribing information for ivacaftor
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
| Ivacaftor | Voriconazole | |
|---|---|---|
| Labeled for | n/a | Fungal infections |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | n/a | $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