What the FDA labels say about taking them together
Azathioprine and infliximab
Infliximab's FDA label of August 28, 2026 names azathioprine in its boxed warning section; the azathioprine label PlainMeds reads does not name infliximab. The infliximab label: “Due to the risk of HSTCL carefully assess the risk/benefit especially if the patient has Crohn's disease or ulcerative colitis, is male, and is receiving azathioprine or 6-mercaptopurine treatment.”
Check it at the source: the azathioprine FDA label on DailyMed (effective November 8, 2025, Sebela Pharmaceuticals Inc.); the infliximab FDA label on DailyMed (effective August 28, 2026).
What does the azathioprine label say about infliximab?
Azathioprine's label (effective November 8, 2025) does not name infliximab in these sections. A label lists what its studies and reports found; it is not a complete list.
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 infliximab label say about azathioprine?
Infliximab label, boxed warningAlmost all had received azathioprine or 6- mercaptopurine concomitantly with a TNF blocker at or prior to diagnosis.
Infliximab label, warnings and precautionsDue to the risk of HSTCL carefully assess the risk/benefit especially if the patient has Crohn's disease or ulcerative colitis, is male, and is receiving azathioprine or 6-mercaptopurine treatment. ( 5.2 ) Hepatitis B virus reactivation – test for HBV infection before starting RENFLEXIS. Monitor HBV carriers during and several months after therapy.
Inflectra label (Pfizer Laboratories Div Pfizer Inc, July 28, 2026), warnings and precautionsDue to the risk of HSTCL carefully assess the risk/benefit especially if the patient has Crohn's disease or ulcerative colitis, is male, and is receiving azathioprine or 6-mercaptopurine treatment.
Source: FDA drug label (Inflectra, BLA125544), Pfizer Laboratories Div Pfizer Inc, effective July 28, 2026 (SPL set 37eaca10-d812-48bc-8b8e-b836bfa9968f), via openFDA
Source: FDA drug label (Avsola, BLA761086), Amgen, Inc, effective July 22, 2026 (SPL set de34bcb7-b524-45c8-9181-61c6f48d540e), via openFDA
Source: FDA drug label (Renflexis), Organon LLC, effective August 28, 2026 (SPL set dbf738c4-3fac-4422-a9d8-51d9c83a8789), 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 | Infliximab | |
|---|---|---|
| Labeled for | Organ transplant rejection, Rheumatoid arthritis | Rheumatoid arthritis, Crohn's disease and ulcerative colitis |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.124 per tablet 50 mg tablet | n/a |
| 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