Azathioprine
Brand names: Azasan, Azathioprine, Imuran
At a glance
- Medicare prescriptions, 2024
- 256,273
- Medicare drug cost
- $12.1M
- Average cost per prescription
- $47.28
- Clinicians who prescribed it
- 10,339
Where it is prescribed
List the prescribers in any state, county, city or ZIP code →
What it is used for
IMURAN is indicated as an adjunct for the prevention of rejection in renal homotransplantation.
From the FDA-approved prescribing information (label dated November 2025). Full labels on DailyMed (opens in a new tab)
Boxed warning
WARNING - MALIGNANCY Chronic immunosuppression with IMURAN, a purine antimetabolite increases risk of malignancy in humans. Reports of malignancy include post-transplant lymphoma and hepatosplenic T-cell lymphoma (HSTCL) in patients with inflammatory bowel disease. Physicians using this drug should be very familiar with this risk as well as with the mutagenic potential to both men and women and with possible hematologic toxicities. Physicians should inform patients of the risk of malignancy with IMURAN. See WARNINGS.
The FDA’s strongest warning on a label. It doesn’t mean the drug is unsafe for most people; talk to your doctor or pharmacist before stopping or changing any medicine.
Who prescribes it
- Rheumatology 31.9%
- Gastroenterology 22.2%
- Nurse Practitioners 13.0%
- Physician Assistants 7.5%
- Neurology 7.5%
- Internal Medicine 5.4%
- Hepatology 3.0%
- Family Medicine 2.9%
- Pulmonology 2.3%
- Physical Medicine & Rehabilitation (PM&R) 0.7%
- Nephrology (Kidney) 0.7%
- Dermatology 0.5%
All prescribers, by place, name or specialty →
Share of Medicare prescriptions written by each specialty. Select one to list its prescribers.
Trend, 2019–2024
Medicare prescriptions fell 8% from 2019 to 2024.
Biggest change by state since 2019
- Oklahoma +13%
- Kentucky +1%
- Texas −3%
- New York −4%
- Georgia −6%
- Oregon (smallest change) −19%
- Wisconsin (smallest change) −18%
From CMS’s yearly state and national Part D summaries, which count every prescriber, including those CMS leaves out of its per-clinician data (fewer than 11 prescriptions). That is why these totals are higher than the count at the top of this page. Prescriptions include refills.
What it looks like
Pills from 5 makers on file. The same medicine can look different depending on who made it, so check the imprint (the letters and numbers on the pill) with your pharmacist if a refill looks different.
Amneal Pharmaceuticals Ny LLC
| Strength | Looks like | Imprint |
|---|---|---|
| 50 mg | yellow round tablet, 8 mm, scored to split in 2 | 54 043 |
| 75 mg | yellow round tablet, 10 mm, scored to split in 2 | AA 44 |
| 100 mg | yellow round tablet, 11 mm, scored to split in 2 | AA 45 |
Glenmark Pharmaceuticals, Inc
| Strength | Looks like | Imprint |
|---|---|---|
| 50 mg | yellow capsule, 13 mm, scored to split in 2 | |
Legacy Pharma USA Inc.
| Strength | Looks like | Imprint |
|---|---|---|
| 50 mg | yellow double circle tablet, 11 mm, scored to split in 2 | IMURAN 50 |
Nucare Pharmaceuticals,inc.
| Strength | Looks like | Imprint |
|---|---|---|
| 50 mg | yellow double circle tablet, 10 mm, scored to split in 2 | AZA 50 |
Sebela Pharmaceuticals Inc.
| Strength | Looks like | Imprint |
|---|---|---|
| 50 mg | yellow double circle tablet, 11 mm, scored to split in 2 | IMURAN 50 |
Source: DailyMed (U.S. National Library of Medicine), from each maker’s FDA drug listing. A few makers are shown, not every one. Never take a pill you can’t identify; ask a pharmacist.
Industry payments about this drug
No industry payments to clinicians named this drug in 2025.
Recalls and shortages
Not on the FDA drug shortage list.
No FDA-reported recalls since 2020.
Sources: CMS Medicare Part D Prescribers by Provider and Drug (2024; prescriptions include refills, and CMS hides counts under 11 per prescriber); U.S. Food and Drug Administration, openFDA (drug labels, NDC directory, enforcement reports, drug shortages); CMS Open Payments 2025; ClinicalTrials.gov. General information only, not medical advice; not yet reviewed by our medical reviewer.