What the FDA labels say about taking them together
Azathioprine and ribavirin
Azathioprine's FDA label of November 8, 2025 names ribavirin in its drug interactions section, and ribavirin's label names azathioprine too. The ribavirin label: “Discontinue nucleoside reverse transcriptase inhibitors or reduce dose or discontinue interferon, ribavirin or both with worsening toxicities Azathioprine:”
Check it at the source: the azathioprine FDA label on DailyMed (effective November 8, 2025, Sebela Pharmaceuticals Inc.); the ribavirin FDA label on DailyMed (effective February 6, 2024, Aurobindo Pharma Limited).
What does the azathioprine label say about ribavirin?
Azathioprine label, drug interactionsUse with ribavirin: The use of ribavirin for hepatitis C in patients receiving azathioprine has been reported to induce severe pancytopenia and may increase the risk of azathioprine-related myelotoxicity.
Source: FDA drug label (IMURAN), NDA016324 (Legacy), as published by Sebela Pharmaceuticals Inc., effective November 8, 2025 (SPL set 606101a0-6244-7eff-e053-2a91aa0acadd), via openFDA; the full label on DailyMed
What does the ribavirin label say about azathioprine?
Ribavirin label, drug interactionsDiscontinue nucleoside reverse transcriptase inhibitors or reduce dose or discontinue interferon, ribavirin or both with worsening toxicities (7.1) Azathioprine:
Ribavirin label, warnings and precautionsMonitor hepatic function during treatment and discontinue treatment for hepatic decompensation (5.3) Severe hypersensitivity reactions including urticaria, angioedema, bronchoconstriction, and anaphylaxis, and serious skin reactions such as Stevens-Johnson syndrome (5.4) Pulmonary disorders, including pulmonary function impairment and pneumonitis, including fatal cases of pneumonia (5.5) Severe depression and suicidal ideation, autoimmune and infectious disorders, suppression of bone marrow function, pancreatitis, and diabetes (5) Bone marrow suppression with azathioprine coadministration (5.6) Growth impairment with combination therapy in pediatric patients
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
| Azathioprine | Ribavirin | |
|---|---|---|
| Labeled for | Organ transplant rejection, Rheumatoid arthritis | Hepatitis C |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.124 per tablet 50 mg tablet | $0.451 per tablet 200 mg tablet |
| Shortage now | No current entry | 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