What the FDA labels say about taking them together
Ivacaftor and posaconazole
Ivacaftor's FDA label of March 23, 2026 names posaconazole in its drug interactions section; the posaconazole labels PlainMeds reads (2) do not name ivacaftor. The ivacaftor label: “… concomitant strong CYP3A inhibitors, such as ketoconazole, itraconazole, posaconazole, voriconazole, telithromycin, and clarithromycin.”
Check it at the source: the ivacaftor FDA label on DailyMed (effective March 23, 2026, Vertex Pharmaceuticals Incorporated); the posaconazole FDA label on DailyMed (effective August 3, 2026, Aurobindo Pharma Limited).
What does the ivacaftor label say about posaconazole?
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 posaconazole label say about ivacaftor?
Posaconazole's label (effective August 3, 2026) and its 1 other brand-application label do not name ivacaftor in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (POSACONAZOLE), Aurobindo Pharma Limited, effective August 3, 2026 (SPL set f8a26673-261c-4e8e-b1e1-9e23aaf7f285), 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 | Posaconazole | |
|---|---|---|
| Labeled for | n/a | Fungal infections |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | n/a | $2.03 per tablet 100 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