What the FDA labels say about taking them together
Itraconazole and phenobarbital
Itraconazole's FDA label of July 13, 2026 names phenobarbital in its drug interactions section; the phenobarbital labels PlainMeds reads (2) do not name itraconazole. The itraconazole label: “Anticonvulsants Phenobarbital Phenytoin Not recommended 2 weeks before and during TOLSURA treatment.”
Check it at the source: the itraconazole FDA label on DailyMed (effective July 13, 2026, Janssen Pharmaceuticals, Inc.); the phenobarbital FDA label on DailyMed (effective August 27, 2026).
What does the itraconazole label say about phenobarbital?
Itraconazole label, drug interactionsAnticonvulsants Phenobarbital Phenytoin Not recommended 2 weeks before and during SPORANOX ® treatment.
Source: FDA drug label (Tolsura, NDA208901), Mayne Pharma Commercial LLC, effective April 23, 2025 (SPL set 306352d1-9d5a-49ad-b72d-893b99546861), via openFDA
Source: FDA drug label (SPORANOX), Janssen Pharmaceuticals, Inc., effective July 13, 2026 (SPL set a4d555fa-787c-40fb-bb7d-b0d4f7318fd0), via openFDA; the full label on DailyMed
What does the phenobarbital label say about itraconazole?
Phenobarbital's label (effective August 27, 2026) and its 1 other brand-application label do not name itraconazole in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Phenobarbital), Chartwell RX, LLC, effective August 27, 2026 (SPL set 74428144-fb24-40a5-a670-3b876e2d116c), 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
| Itraconazole | Phenobarbital | |
|---|---|---|
| Labeled for | Fungal infections | Seizures and epilepsy |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.910 per capsule 100 mg capsule | $0.213 per tablet 100 mg tablet |
| Shortage now | A presentation being discontinued | 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