What the FDA labels say about taking them together
Peginterferon alfa 2a and ribavirin
Peginterferon alfa 2a's FDA label of September 2, 2026 names ribavirin in its contraindications section, and ribavirin's label names peginterferon alfa 2a too. The ribavirin label: “Ribavirin tablets and PEGASYS ® combination therapy are contraindicated in patients with: Autoimmune hepatitis.”
Check it at the source: the peginterferon alfa 2a FDA label on DailyMed (effective September 2, 2026); the ribavirin FDA label on DailyMed (effective February 6, 2024, Aurobindo Pharma Limited).
What does the peginterferon alfa 2a label say about ribavirin?
Peginterferon alfa 2a label, contraindicationsPEGASYS combination treatment with ribavirin is contraindicated in women who are pregnant and men whose female partners are pregnant [See Warnings and Precautions (5.1) and Use in Specific Populations (8.1) ].
Peginterferon alfa 2a label, drug interactionsReduce or discontinue the dose of PEGASYS or ribavirin or both should the events worsen ( 7.4 ) Zidovudine: monitor for worsening neutropenia and/or anemia with PEGASYS and/or ribavirin
Peginterferon alfa 2a label, warnings and precautionsUse with ribavirin Birth defects and fetal death: patients must have a negative pregnancy test prior to therapy, use 2 forms of effective contraception, and have monthly pregnancy tests ( 5.1 ) PEGASYS Clinically Significant Adverse Reactions or Risks Patients exhibiting the following events should be closely monitored and may require dose reduction or discontinuation of therapy:
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
What does the ribavirin label say about peginterferon alfa 2a?
Ribavirin label, contraindicationsRibavirin tablets and PEGASYS ® combination therapy are contraindicated in patients with: Autoimmune hepatitis.
Ribavirin label, drug interactionsPatients receiving PEGASYS ® /ribavirin and NRTIs should be closely monitored for treatment-associated toxicities.
Ribavirin label, warnings and precautionsThe PEGASYS ® Package Insert should be reviewed in its entirety for additional safety information prior to initiation of combination treatment.
Source: FDA drug label (Ribavirin), Aurobindo Pharma Limited, effective February 6, 2024 (SPL set eee304d0-c2ea-44f4-97d9-92a414d31b6c), 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
| Peginterferon alfa 2a | Ribavirin | |
|---|---|---|
| Labeled for | Hepatitis C, Hepatitis B | Hepatitis C |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | n/a | $0.451 per tablet 200 mg tablet |
| Shortage now | Resolved | No current entry |
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