What the FDA labels say about taking them together
Methadone and peginterferon alfa 2a
Peginterferon alfa 2a's FDA label of September 2, 2026 names methadone in its drug interactions section; the methadone labels PlainMeds reads (4) do not name peginterferon alfa 2a. The peginterferon alfa 2a label: “DRUG INTERACTIONS Drugs metabolized by CYP1A2: monitor for increased serum levels of theophylline and adjust dose accordingly Methadone: monitor for signs and symptoms of methadone toxicity Nucleoside analogues: closely …”
Check it at the source: the methadone FDA label on DailyMed (effective December 8, 2025, Epic Pharma, LLC); the peginterferon alfa 2a FDA label on DailyMed (effective September 2, 2026).
What does the methadone label say about peginterferon alfa 2a?
Methadone's label (effective December 8, 2025) and its 3 other brand-application labels do not name peginterferon alfa 2a 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 peginterferon alfa 2a label say about methadone?
Peginterferon alfa 2a label, drug interactionsDRUG INTERACTIONS Drugs metabolized by CYP1A2: monitor for increased serum levels of theophylline and adjust dose accordingly ( 7.2 ) Methadone: monitor for signs and symptoms of methadone toxicity ( 7.3 ) Nucleoside analogues: closely monitor for toxicities.
Source: FDA drug label (Pegasys), pharmaand GmbH, effective September 2, 2026 (SPL set d9290e5b-6d40-2318-e053-2995a90a9916), 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 | Peginterferon alfa 2a | |
|---|---|---|
| Labeled for | Pain, Opioid use disorder | Hepatitis C, Hepatitis B |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.177 per tablet 10 mg tablet | n/a |
| Shortage now | No current entry | Resolved |
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