What the FDA labels say about taking them together
Methadone and voriconazole
Voriconazole's FDA label of February 26, 2026 names methadone in its drug interactions section; the methadone labels PlainMeds reads (4) do not name voriconazole. The voriconazole label: “Increased plasma concentrations of methadone have been associated with toxicity including QT prolongation. Frequent monitoring for adverse reactions and toxicity related to methadone is recommended when concomitantly …”
Check it at the source: the methadone FDA label on DailyMed (effective December 8, 2025, Epic Pharma, LLC); the voriconazole FDA label on DailyMed (effective February 26, 2026, Roerig).
What does the methadone label say about voriconazole?
Methadone's label (effective December 8, 2025) and its 3 other brand-application labels do not name voriconazole in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Methadone Hydrochloride), Epic Pharma, LLC, effective December 8, 2025 (SPL set 6da7501b-b881-4bc7-891a-74214a00a3ac), via openFDA; the full label on DailyMed
What does the voriconazole label say about methadone?
Voriconazole label, drug interactionsDrug/Drug Class (Mechanism of Interaction by Voriconazole): Methadone Results based on in vivo clinical study following repeat oral dosing with 400 mg every 12 hours for 1 day, then 200 mg every 12 hours for 4 days voriconazole to subjects receiving a methadone maintenance dose (30–100 mg every 24 hours) (CYP3A4 Inhibition); Drug Plasma Exposure (C max and AUC τ): Increased; Prevention or Management Recommendations: Increased plasma concentrations of methadone have been associated with toxicity including QT prolongation. Frequent monitoring for adverse reactions and toxicity related to methadone is recommended when concomitantly administered with VFEND. …
Voriconazole label (Xellia Pharmaceuticals USA LLC, January 11, 2023), drug interactionsMethadone (CYP3A4 Inhibition) Increased Increased plasma concentrations of methadone have been associated with toxicity including QT prolongation.
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
| Methadone | Voriconazole | |
|---|---|---|
| Labeled for | Pain, Opioid use disorder | Fungal infections |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.177 per tablet 10 mg tablet | $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