HomeNDC LookupIngredientsAzathioprine Sodium › 00143-9566-01
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Azathioprine Sodium 100 mg/10mL Injection, Powder, Lyophilized, For Solution

by Hikma Pharmaceuticals USA Inc. · 1 VIAL in 1 BOX, UNIT-DOSE (0143-9566-01) / 10 mL in 1 VIAL
NDC 00143-9566-01
🏷️ FDA NDC (as labeled) 0143-9566-01 billing pads the labeler segment with a zero
Rx only Generic On market Non-controlled
🗂️ Data synced Jul 24, 2026 · sources: openFDA · FDA label (DailyMed) · FDA Orange & Purple Book · First Databank · CMS NADAC, ASP, Medicare & Medicaid · RxNorm
📋 All sources & update times →

🆔 Identity & classification

FDA NDC (as labeled) 0143-9566-01
Product NDC 0143-9566
11-digit billing NDC 00143956601
NCPDP billing unit EA — each (per item)
RxCUI 239983
UNII AM94R510MS
Application # ANDA074419
SPL Set ID 9ffe79a1-ac91-4a7b-a9e3-7c84bfa9ddf0
Established class (EPC) Purine Antimetabolite
Mechanism of action Nucleic Acid Synthesis Inhibitors
Chemical class Nucleosides; Purines
DEA schedule Non-controlled
Marketing category ANDA
Marketing status On market
FDA listing status Listed (active directory)
Marketing start 1995-05-01
Route INTRAVENOUS
Dosage form INJECTION, POWDER, LYOPHILIZED, FOR SOLUTION
Substance AZATHIOPRINE SODIUM
GPI-14 99406010102110
GPI class azaTHIOprine Sodium
GCN Seq No 011681
GCN 46760
HICL code 007825
Ingredient (HICL) Azathioprine Sodium
HIC1 code Z
Therapeutic class — broad (HIC1) Body As A Whole
HIC2 code Z2
Therapeutic class — intermediate (HIC2) Antihistamines, Antiserotonins, Immunosuppressants
HIC3 code Z2E
Therapeutic class — specific (HIC3) Immunosuppressives
AHFS code 90:28.08.92
AHFS class Antimetabolites, Immunosupp Therapy Misc
FDB label name AZATHIOPRINE SOD 100 MG VIAL
FDB brand name Azathioprine Sodium
Legend status F — Federal legend — prescription drug or device
Why two NDCs? The FDA registers this code as 0143-9566-01 — a 4-4-2 layout, and that's what's printed on the package and shown on DailyMed. For insurance claims, every NDC is standardized to a uniform 11-digit 5-4-2 format by adding a zero to the labeler segment → 00143-9566-01. Same drug, same package — only the format differs.
Where does this data come from?
Identifiers from the FDA openFDA NDC Directory and Structured Product Labeling; RxCUI from RxNorm (NLM); GPI from Medi-Span; GCN / HIC / AHFS / legend from First Databank.

🏷️ RxNorm drug class

This medicine belongs to the Purine Antimetabolite class.

Pharmacologic class Purine Antimetabolite
Drug family (ATC) Other immunosuppressants
How it works Nucleic Acid Synthesis Inhibitors
Where does this data come from?
Therapeutic classes from RxNorm RxClass (U.S. National Library of Medicine) — Established Pharmacologic Class (FDA), ATC drug family (WHO) and mechanism of action, matched by this product’s RxCUI.

🏭 Manufacturer & labeler

LabelerHikma Pharmaceuticals USA Inc.
Application holderHIKMA PHARMACEUTICALS USA INC
FDA applicationANDA074419 (ANDA)
Labeler code00143
First marketedMay 1995
Product typeHuman Prescription Drug
Portfolio720 products on file
The labeler markets the product; the application holder owns the FDA approval. They’re often the same company but can differ (e.g. a repackager or an authorized generic). A mailing address / phone appears here when the manufacturer includes it in the product’s FDA label (not all do).
Where does this data come from?
Labeler, application holder and registered establishment from the FDA openFDA NDC Directory and Drugs@FDA; address/contact from the product’s FDA label.

🩺 Clinical

Label name AZATHIOPRINE SOD 100 MG VIAL Ingredient Azathioprine Sodium
📗 Our plain-language guide HelloPharmacist
  • You're right that it treats two quite different conditions, but the common thread is the immune system. After a kidney transplant, your immune system sees the new kidney as foreign...
  • What exactly is azathioprine being used for — it seems like a drug used for very different things?
  • Azathioprine is not a quick fix — it typically takes 6 to 8 weeks before you start feeling any improvement, and your doctor will usually give it a full 12 weeks before deciding if...
  • How long will it take before I notice it working for my rheumatoid arthritis?
📖 Read our full Azathioprine guide →
1
Nutrient depletion considerations

Azathioprine may be associated with lower levels of 1 nutrient — worth a chat with your pharmacist, not a cause for alarm.

An association is not a deficiency. Educational only — don't start or stop anything without professional guidance.
Where does this data come from?
Plain-language summary from MedlinePlus (U.S. National Library of Medicine); supplement & herbal interactions and nutrient depletion data from the Natural Medicines database; our full guide is HelloPharmacist editorial content.

🧪 Inactive Ingredients / Excipients

Inactive ingredients, also called excipients, are components of the drug product other than the active ingredient. They may include fillers, dyes, coatings, preservatives, flavors, or other formulation ingredients.

💡 Tap an ingredient (hover on desktop) to see what it is and why it’s used.

  • UNII QTT17582CB
    A strong acid used to adjust and maintain the proper pH level in liquid medicines, ensuring stability and preventing breakdown of active ingredients.
  • UNII 55X04QC32I
    A strong alkaline chemical used to adjust and maintain the pH balance of liquid medicines. It helps keep the medicine stable and ensures it stays effective during storage.

2 inactive ingredients listed in the exact product block matched to this NDC.

Where does this data come from?
Data sourced from official FDA Structured Product Labeling (SPL) via DailyMedingredient classCode="IACT" elements from the exact product block matched by this NDC. Label-section narrative from DailyMed / the openFDA label index is shown separately when available.

Inactive ingredient FAQ

Are inactive ingredients the same for every manufacturer?
No. Inactive ingredients can differ by manufacturer, dosage form, strength, and package / product version.
Why might an inactive ingredient be missing?
Some SPLs do not provide a complete structured inactive-ingredient list, and older or unusual labels may only include the information in narrative text.
Can inactive ingredients matter?
Yes. They can matter for allergies, intolerances, dyes, gluten / lactose concerns, preservatives, and formulation differences — but confirm with a pharmacist or the manufacturer when it’s clinically important.

💲 Pricing

A drug doesn't have one price. Each row is a different public payment system, and none is what you'd pay at the counter — that depends on your insurance. The ⓘ on each row explains what it measures.

Price systemPer mLPer package
Retail pharmacies payNADAC · weekly Not in the retail survey — common for institutional, discontinued, or low-volume packs.
Medicaid paysCMS SDUD · 12 mo No recent Medicaid claims on file for this NDC — rare and low-volume NDCs are suppressed in the public data.
Medicare drug plans payPart D · quarterly No Part D plan price is available for this NDC in our data.
Medicare Part B allowsASP · J7501 No ASP payment limit on file for J7501 this quarter.
ℹ️
No price is published for this exact package yet. CMS surveys NADAC per package size, so a different pack of the same drug often has one.
Where does this data come from?
NADAC (National Average Drug Acquisition Cost) is the CMS weekly pharmacy-acquisition-cost survey — what pharmacies pay. ASP (Average Sales Price) is the CMS Medicare Part B drug-payment file, published quarterly. Medicaid pays is computed by us from CMS State Drug Utilization Data (total reimbursed ÷ units, trailing 12 months) — gross of rebates and inclusive of dispensing fees, so it reflects what Medicaid paid, not an acquisition cost. Medicare drug plans pay is the median negotiated point-of-sale unit cost across plans listing this NDC in the CMS quarterly Prescription Drug Plan pricing files, before rebates. The VA pays is the federal contract price (FSS, and the statutory Big 4 ceiling where listed) from the VA National Acquisition Center pharmaceutical price file. All are free public government data; each measures a different payer, so the figures are not directly comparable.

🧾 Billing & reimbursement

FDA NDC (as labeled)0143-9566-01
11-digit billing NDC00143-9566-01
Format4-4-2 as registered → padded to 5-4-2 for billing (zero added to the labeler segment)
HCPCS J-codeJ7501
DescriptorAZATHIOPRINE, PARENTERAL, 100 MG
Billing units / pkg1 units
Crosswalk sourcePDAC NDC-HCPCS crosswalk (DME MAC / DMEPOS)
Where does this data come from?
The HCPCS J-code crosswalk comes from the CMS ASP NDC-HCPCS crosswalk and the DMEPDAC (DME MAC) NDC-HCPCS crosswalk — free public CMS data. Billing units are derived from the code’s descriptor and the package amount.

🔁 Therapeutic equivalents

ProductLabelerPackNADAC/unitTEStatusPrice vs. this
Azathioprine Sodium 100 mg/10mLthis 00143-9566-01 Hikma 1 vial FDA listed
About this product: this is a generic version of the medicine. FDA equivalence ratings are shown when available, and other versions are listed above, least expensive first.
Where does this data come from?
Equivalents are other NDCs of the same ingredient, form and route from the openFDA NDC Directory, ranked least-expensive-first by NADAC. Therapeutic-equivalence (AB) ratings come from the FDA Orange Book; biologics use the FDA Purple Book for biosimilar & interchangeable status.

Availability & generic status

🏛️
1995
On the market since
May 1995
📍
2026
Currently FDA-listed
31 years listed
🔓
·
Generic on the market
this product is a generic
This is a generic drug

This product is an FDA-approved generic. Other versions of the same drug are listed under Therapeutic equivalents, least expensive first.

Where does this data come from?
Patents and exclusivity from the FDA Orange Book (small-molecule drugs), refreshed from public FDA data. Generic launch timing is an estimate, not a guarantee.

🔬 Reported adverse events (FAERS)

Read carefully: FAERS reports are voluntary and unverified. Counts are not incidence, do not establish causation, are subject to reporting bias, and cannot be used to compare one drug to another. Shown for signal context only. Reports for Azathioprine Sodium — the ingredient across all brands.

Top reported reactions

Condition Aggravated695
Fatigue535
Arthralgia534
Drug Intolerance462
Headache454
Hepatic Enzyme Increased447
Alopecia428

Age at onset

Neonate17
Infant2
Child3
Adolescent9
Adult596
Elderly65

Reporter sex

2,501 reports
Male · 35%
Female · 65%

Serious outcomes

Hospitalization1,291
Death753
Disabling627
Reports over time (by year) — tap or hover for the count & year
2019 2021 2023 2026 310 0
Most recent year is provisional (FAERS lags ~3 months).
Where does this data come from?
Adverse-event reports from the FDA Adverse Event Reporting System (FAERS) via openFDA. FAERS reports are voluntary and unverified — counts are not incidence and don’t establish causation.

📦 Packaging — all sizes for this product

Package NDCDescription Marketing startStatus
00143-9566-01 You're viewing this 1 VIAL in 1 BOX, UNIT-DOSE (0143-9566-01) / 10 mL in 1 VIAL 1995-05-01 Active

🧭 About this NDC listing & data coverage

Finished prescription product
What data is (and isn’t) available for this NDC — tap to expand
NDC identity (package / product / labeler codes) ✓ Available
Labeler ✓ Available
Product & package description ✓ Available
Marketing category & status ✓ Available
Active ingredient / dosage form / route ✓ Available
FDA label (SPL via DailyMed) ✓ Available
Package photos — Not published for this NDC No photo available yet for this listing.
Inactive ingredients (structured) ✓ Available
NADAC pharmacy acquisition price (CMS) — Not published for this NDC CMS publishes NADAC only for NDCs reported in its retail-pharmacy survey.
Orange Book / therapeutic-equivalence data — Not published for this NDC Applies only to products approved under an NDA/ANDA; many listings are out of scope.
HCPCS J-code billing crosswalk ✓ Available
Medicaid utilization (CMS SDUD) — Not published for this NDC CMS reports utilization only for NDCs with Medicaid claims above its privacy threshold.
“Not published” reflects what the public FDA / CMS / NLM sources provide for this exact package code — it is a property of the data feeds, not a judgment about the product.

Questions about this listing

Why is there no price listed?
The pricing shown on our NDC pages comes from CMS NADAC, a voluntary survey of retail community pharmacy invoices. CMS does not publish a NADAC for every NDC — packages outside the retail survey (institutional and hospital products, bulk packages, discontinued items, and many OTC items) may never receive one. A missing price reflects the survey's scope, not this product's actual cost, and does not mean the product is free or unavailable.
Is the NDC printed on the package the same as the 11-digit billing NDC?
Yes, they identify this exact package in different formats. The FDA registers it as 0143-9566-01, which is what is printed on the packaging and shown on DailyMed. Insurance claims use a fixed 11-digit 5-4-2 format, so the short segment is padded with a leading zero: 00143-9566-01, written without dashes as 00143956601. The Identity section at the top of this page lists every form of this code.
What do the three segments of this NDC mean?
In 00143-9566-01, the first segment (00143) is the labeler code FDA assigned to Hikma Pharmaceuticals USA Inc.; the middle segment (9566) identifies this specific product — its ingredient, strength, and dosage form; and the last segment (01) identifies this exact package size and type. Together they name one specific package of one specific product.
Is this package still being marketed?
Yes, per the latest FDA NDC Directory data on this page: this package is listed as actively marketed, with no marketing end date reported by Hikma Pharmaceuticals USA Inc.. Listing status can change — the directory data on this page refreshes weekly.
Who lists this product with the FDA?
Hikma Pharmaceuticals USA Inc. is the labeler of record for this NDC — the company under whose FDA-assigned code the package is listed. The labeler may be the manufacturer itself or a distributor marketing the product under its own code.
Do I need a prescription for this product?
This NDC is listed with FDA as a prescription product, so it is dispensed under a prescriber's order. Your pharmacist can tell you whether any over-the-counter forms of the same medication exist.
Does this product have a billing J-code?
Yes — this NDC cross-references HCPCS code J7501 for medical-claim billing (typically used when a product is administered in a clinical setting rather than dispensed at a retail pharmacy). See the Billing section on this page.
This page identifies an FDA-listed package (the NDC) and reports public regulatory and pricing data about the listing. It is reference information, not a medical recommendation — talk to your pharmacist or prescriber about your own medication.
Where does this data come from?
Listing facts (marketing category, packager status, marketing dates) from the FDA openFDA NDC Directory; label availability from DailyMed; pricing coverage from CMS NADAC; equivalence scope from the FDA Orange Book.

📄 Full prescribing information FDA SPL

The complete FDA label for this product — the official prescribing information, verbatim, section by section. Jump with a chip, search within the label, or expand everything.
🚨 Boxed Warning 75 words

WARNING - MALIGNANCY Chronic immunosuppression with azathioprine, 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 azathioprine. See WARNINGS .

🎯 Indications and Usage 165 words

INDICATIONS AND USAGE Azathioprine Sodium for Injection, USP is indicated as an adjunct for the prevention of rejection in renal homotransplantation. It is also indicated for the management of active rheumatoid arthritis to reduce signs and symptoms. Renal Homotransplantation Azathioprine is indicated as an adjunct for the prevention of rejection in renal homotransplantation.

Experience with over 16,000 transplants shows a five-year patient survival of 35% to 55%, but this is dependent on donor, match for HLA antigens, anti-donor or anti-B-cell alloantigen antibody and other variables. The effect of azathioprine on these variables has not been tested in controlled trials. Rheumatoid Arthritis Azathioprine is indicated for the treatment of active rheumatoid arthritis (RA) to reduce signs and symptoms.

Aspirin, non-steroidal anti-inflammatory drugs and/or low dose glucocorticoids may be continued during treatment with azathioprine. The combined use of azathioprine with disease modifying anti-rheumatic drugs (DMARDs) has not been studied for either added benefit or unexpected adverse effects. The use of azathioprine with these agents cannot be recommended.

⏱️ Dosage and Administration ~3 min read

DOSAGE AND ADMINISTRATION Renal Homotransplantation The dose of azathioprine required to prevent rejection and minimize toxicity will vary with individual patients; this necessitates careful management. The initial dose is usually 3 to 5 mg/kg daily, beginning at the time of transplant. Azathioprine is usually given as a single daily dose on the day of, and in a minority of cases 1 to 3 days before, transplantation.

Azathioprine is often initiated with the intravenous administration of the sodium salt, with subsequent use of tablets (at the same dose level) after the postoperative period. Intravenous administration of the sodium salt is indicated only in patients unable to tolerate oral medications. Dose reduction to maintenance levels of 1 to 3 mg/kg daily is usually possible.

The dose of azathioprine should not be increased to toxic levels because of threatened rejection. Discontinuation may be necessary for severe hematologic or other toxicity, even if rejection of the homograft may be a consequence of drug withdrawal. Rheumatoid Arthritis Azathioprine is usually given on a daily basis.

The initial dose should be approximately 1 mg/kg (50 to 100 mg) given as a single dose or on a twice-daily schedule. The dose may be increased, beginning at 6 to 8 weeks and thereafter by steps at 4-week intervals, if there are no serious toxicities and if initial response is unsatisfactory. Dose increments should be 0.5 mg/kg daily, up to a maximum dose of 2.5 mg/kg/day.

Therapeutic response occurs after several weeks of treatment, usually 6 to 8; an adequate trial should be a minimum of 12 weeks. Patients not improved after 12 weeks can be considered refractory. Azathioprine may be continued long-term in patients with clinical response, but patients should be monitored carefully, and gradual dosage reduction should be attempted to reduce risk of toxicities.

Maintenance therapy should be at the lowest effective dose, and the dose given can be lowered decrementally with changes of 0.5 mg/kg or approximately 25 mg daily every 4 weeks while other therapy is kept constant. The optimum duration of maintenance azathioprine has not been determined. Azathioprine can be discontinued abruptly, but delayed effects are possible.

Patients with TPMT and/or NUDT15 Deficiency Consider testing for TPMT and NUDT15 deficiency in patients who experience severe bone marrow toxicities. Early drug discontinuation may be considered in patients with abnormal CBC results that do not respond to dose reduction (see CLINICAL PHARMACOLOGY , WARNINGS: Cytopenias , and PRECAUTIONS: Laboratory Tests ). Homozygous deficiency in either TPMT or NUDT15 Because of the risk of increased toxicity, consider alternative therapies for patients who are known to have TPMT or NUDT15 deficiency (see CLINICAL PHARMACOLOGY , WARNINGS: Cytopenias , and PRECAUTIONS: Laboratory Tests ).

Heterozygous deficiency in TPMT and/or NUDT15 Because of the risk of increased toxicity, dosage reduction is recommended in patients known to have heterozygous deficiency of TPMT or NUDT15. Patients who are heterozygous for both TPMT and NUDT15 deficiency may require more substantial dosage reductions (see CLINICAL PHARMACOLOGY , WARNINGS: Cytopenias , and PRECAUTIONS: Laboratory Tests ). Use in Renal Dysfunction Relatively oliguric patients, especially those with tubular necrosis in the immediate postcadaveric transplant period, may have delayed clearance of azathioprine or its metabolites, may be particularly sensitive to this drug, and are usually given lower doses.

Parenteral Administration Add 10 mL of Sterile Water for Injection, and swirl until a clear solution results. This solution, equivalent to 100 mg azathioprine, is for intravenous use only; it has a pH of approximately 9.6, and it should be used within 24 hours. Further dilution into sterile saline or dextrose is usually made for infusion; the final volume depends on time for the infusion, usually 30 to 60 minutes, but as short as 5 minutes and…

Contraindications 55 words

CONTRAINDICATIONS Azathioprine Sodium for Injection should not be given to patients who have shown hypersensitivity to the drug. Azathioprine should not be used for treating rheumatoid arthritis in pregnant women. Patients with rheumatoid arthritis previously treated with alkylating agents (cyclophosphamide, chlorambucil, melphalan or others) may have a prohibitive risk of malignancy if treated with azathioprine.

⚠️ Warnings ~3 min read

WARNINGS Malignancy: Patients receiving immunosuppressants, including azathioprine, are at increased risk of developing lymphoma and other malignancies, particularly of the skin. Physicians should inform patients of the risk of malignancy with azathioprine. As usual for patients with increased risk for skin cancer, exposure to sunlight and ultraviolet light should be limited by wearing protective clothing and using a sunscreen with a high protection factor.

Post-transplant: Renal transplant patients are known to have an increased risk of malignancy, predominantly skin cancer and reticulum cell or lymphomatous tumors. The risk of post-transplant lymphomas may be increased in patients who receive aggressive treatment with immunosuppressive drugs, including azathioprine. Therefore, immunosuppressive drug therapy should be maintained at the lowest effective levels.

Rheumatoid Arthritis: Information is available on the risk of malignancy with the use of azathioprine in rheumatoid arthritis (see ADVERSE REACTIONS ). It has not been possible to define the precise risk of malignancy due to azathioprine. The data suggest the risk may be elevated in patients with rheumatoid arthritis, though lower than for renal transplant patients.

However, acute myelogenous leukemia as well as solid tumors have been reported in patients with rheumatoid arthritis who have received azathioprine. Inflammatory Bowel Disease: Postmarketing cases of hepatosplenic T-cell lymphoma (HSTCL), a rare type of T-cell lymphoma, have been reported in patients treated with azathioprine. These cases have had a very aggressive disease course and have been fatal.

The majority of reported cases have occurred in patients with Crohn's disease or ulcerative colitis and the majority were in adolescent and young adult males. Some of the patients were treated with azathioprine as monotherapy and some had received concomitant treatment with a TNFα blocker at or prior to diagnosis. The safety and efficacy of azathioprine for the treatment of Crohn's disease and ulcerative colitis have not been established.

Cytopenias: Severe leukopenia, thrombocytopenia, anemias including macrocytic anemia, and/or pancytopenia may occur in patients being treated with azathioprine. Severe bone marrow suppression may also occur. Hematologic toxicities are dose-related and may be more severe in renal transplant patients whose homograft is undergoing rejection.

It is suggested that patients on azathioprine have complete blood counts, including platelet counts, weekly during the first month, twice monthly for the second and third months of treatment, then monthly or more frequently if dosage alterations or other therapy changes are necessary. Delayed hematologic suppression may occur. Prompt reduction in dosage or temporary withdrawal of the drug may be necessary if there is a rapid fall in or persistently low leukocyte count, or other evidence of bone marrow depression.

Leukopenia does not correlate with therapeutic effect; therefore the dose should not be increased intentionally to lower the white blood cell count. TPMT or NUDT15 Deficiency Patients with thiopurine S-methyl transferase (TPMT) or nucleotide diphosphatase (NUDT15) deficiency may be at an increased risk of severe and life-threatening myelotoxicity if receiving conventional doses of azathioprine (see CLINCIAL PHARMACOLOGY ). Death associated with pancytopenia has been reported in patients with absent TPMT activity receiving azathioprine.

In patients with severe myelosuppression, consider evaluation for TPMT and NUDT15 deficiency (see PRECAUTIONS: Laboratory Tests ). Consider alternative therapy in patients with homozygous TPMT or NUDT15 deficiency and reduced dosages in patients with heterozygous deficiency (see DOSAGE AND ADMINISTRATION ). Serious infections: Patients receiving immunosuppressants, including azathioprine, are at increased risk for bacterial, viral, fungal, protozoal, and opportunistic infections, including reactivation…

🤒 Adverse Reactions ~2 min read

ADVERSE REACTIONS The principal and potentially serious toxic effects of azathioprine are hematologic and gastrointestinal. The risks of secondary infection and malignancy are also significant (see WARNINGS ). The frequency and severity of adverse reactions depend on the dose and duration of azathioprine as well as on the patient’s underlying disease or concomitant therapies.

The incidence of hematologic toxicities and neoplasia encountered in groups of renal homograft recipients is significantly higher than that in studies employing azathioprine for rheumatoid arthritis. The relative incidences in clinical studies are summarized below: Toxicity Renal Homograft Rheumatoid Arthritis Leukopenia (any degree) <2500 cells/mm 3 Infections >50% 16% 20% 28% 5.3% <1% Neoplasia Lymphoma Others 0.5% 2.8% Data on the rate and risk of neoplasia among persons with rheumatoid arthritis treated with azathioprine are limited.

The incidence of lymphoproliferative disease in patients with RA appears to be significantly higher than that in the general population. In one completed study, the rate of lymphoproliferative disease in RA patients receiving higher than recommended doses of azathioprine (5 mg/kg/day) was 1.8 cases per 1000 patient-years of follow-up, compared with 0.8 cases per 1000 patient-years of follow-up in those not receiving azathioprine. However, the proportion of the increased risk attributable to the azathioprine dosage or to other therapies (i.e., alkylating agents) received by patients treated with azathioprine cannot be determined.

Hematologic Leukopenia and/or thrombocytopenia are dose-dependent and may occur late in the course of therapy with azathioprine. Dose reduction or temporary withdrawal may result in reversal of these toxicities. Infection may occur as a secondary manifestation of bone marrow suppression or leukopenia, but the incidence of infection in renal homotransplantation is 30 to 60 times that in rheumatoid arthritis.

Anemias, including macrocytic anemia and/or bleeding have been reported. Patients with low or absent TPMT or NUDT15 activity are at increased risk for severe, life-threatening myelosuppression from azathioprine (see CLINICAL PHARMACOLOGY , WARNINGS: Cytopenias and PRECAUTIONS: Laboratory Tests , DOSAGE AND ADMINISTRATION ). Gastrointestinal Nausea and vomiting may occur within the first few months of therapy with azathioprine, and occurred in approximately 12% of 676 rheumatoid arthritis patients.

The frequency of gastric disturbance often can be reduced by administration of the drug in divided doses and/or after meals. However, in some patients, nausea and vomiting may be severe and may be accompanied by symptoms such as diarrhea, fever, malaise, and myalgias (see PRECAUTIONS ). Vomiting with abdominal pain may occur rarely with a hypersensitivity pancreatitis.

Hepatotoxicity manifest by elevation of serum alkaline phosphatase, bilirubin, and/or serum transaminases is known to occur following azathioprine use, primarily in allograft recipients. Hepatotoxicity has been uncommon (less than 1%) in rheumatoid arthritis patients. Hepatotoxicity following transplantation most often occurs within 6 months of transplantation and is generally reversible after interruption of azathioprine.

A rare, but life-threatening hepatic veno-occlusive disease associated with chronic administration of azathioprine has been described in transplant patients and in one patient receiving azathioprine for panuveitis. 11, 12, 13 Periodic measurement of serum transaminases, alkaline phosphatase and bilirubin is indicated for early detection of hepatotoxicity. If hepatic veno-occlusive disease is clinically suspected, azathioprine should be permanently withdrawn.

Others Additional side effects of low frequency have been reported. These include skin rashes, alopecia, fever, arthralgias, diarrhea, steatorrhea, negative nitrogen balance, reversible interstitial pneumonitis, hepatosplenic T-cell lymphoma (see Boxed WARNING – M…

🤰 Pregnancy ~2 min read

Pregnancy: Azathioprine can cause fetal harm when administered to a pregnant woman. Azathioprine should not be given during pregnancy without careful weighing of risk versus benefit. Whenever possible, use of azathioprine in pregnant patients should be avoided.

This drug should not be used for treating rheumatoid arthritis in pregnant women. 3 Azathioprine is teratogenic in rabbits and mice when given in doses equivalent to the human dose (5 mg/kg daily). Abnormalities included skeletal malformations and visceral anomalies.

2 Postmarketing cases of intrahepatic cholestasis of pregnancy (ICP) have been reported in women treated with azathioprine during pregnancy. ICP symptoms and elevated bile acid levels improved following azathioprine discontinuation. Discontinue Azathioprine Sodium for Injection if ICP develops in a pregnant woman.

Limited immunologic and other abnormalities have occurred in a few infants born of renal allograft recipients on azathioprine. In a detailed case report, 4 documented lymphopenia, diminished IgG and IgM levels, CMV infection, and a decreased thymic shadow were noted in an infant born to a mother receiving 150 mg azathioprine and 30 mg prednisone daily throughout pregnancy. At ten weeks most features were normalized.

DeWitte et al reported pancytopenia and severe immune deficiency in a preterm infant whose mother received 125 mg azathioprine and 12.5 mg prednisone daily. 5 There have been two published reports of abnormal physical findings. Williamson and Karp described an infant born with preaxial polydactyly whose mother received azathioprine 200 mg daily and prednisone 20 mg every other day during pregnancy.

6 Tallent et al described an infant with a large myelomeningocele in the upper lumbar region, bilateral dislocated hips, and bilateral talipes equinovarus. The father was on long-term azathioprine therapy. 7 Benefit versus risk must be weighed carefully before use of azathioprine in patients of reproductive potential.

There are no adequate and well-controlled studies in pregnant women. If this drug is used during pregnancy or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to the fetus. Women of childbearing age should be advised to avoid becoming pregnant.

Pregnancy Teratogenic Effects: See WARNINGS section.

🧒 Pediatric Use 14 words

Pediatric Use Safety and efficacy of azathioprine in pediatric patients have not been established.

🆘 Overdosage 111 words

OVERDOSAGE The oral LD 50 s for single doses of azathioprine in mice and rats are 2500 mg/kg and 400 mg/kg, respectively. Very large doses of this antimetabolite may lead to marrow hypoplasia, bleeding, infection, and death. About 30% of azathioprine is bound to serum proteins, but approximately 45% is removed during an 8-hour hemodialysis.

14 A single case has been reported of a renal transplant patient who ingested a single dose of 7500 mg azathioprine. The immediate toxic reactions were nausea, vomiting, and diarrhea, followed by mild leukopenia and mild abnormalities in liver function. The white blood cell count, SGOT, and bilirubin returned to normal 6 days after the overdose.

🧬 Clinical Pharmacology ~3 min read

CLINICAL PHARMACOLOGY Azathioprine is well absorbed following oral administration. Maximum serum radioactivity occurs at 1 to 2 hours after oral 35 S-azathioprine and decays with a half-life of 5 hours. This is not an estimate of the half-life of azathioprine itself, but is the decay rate for all 35 S-containing metabolites of the drug.

Because of extensive metabolism, only a fraction of the radioactivity is present as azathioprine. Usual doses produce blood levels of azathioprine, and of mercaptopurine derived from it, which are low (<1 mcg/mL). Blood levels are of little predictive value for therapy since the magnitude and duration of clinical effects correlate with thiopurine nucleotide levels in tissues rather than with plasma drug levels.

Azathioprine and mercaptopurine are moderately bound to serum proteins (30%) and are partially dialyzable. (See OVERDOSAGE ). Azathioprine is metabolized to 6-mercaptopurine (6-MP).

Both compounds are rapidly eliminated from blood and are oxidized or methylated in erythrocytes and liver; no azathioprine or mercaptopurine is detectable in urine after 8 hours. Activation of 6-mercaptopurine occurs via hypoxanthine-guanine phosphoribosyltransferase (HGPRT) and a series of multi-enzymatic processes involving kinases to form 6-thioguanine nucleotides (6-TGNs) as major metabolites. The cytotoxicity of azathioprine is due, in part, to the incorporation of 6-TGN into DNA.

6-MP undergoes two major inactivation routes. One is thiol methylation, which is catalyzed by the enzyme thiopurine S-methyltransferase (TPMT), to form the inactive metabolite methyl-6-MP (6-MeMP). Another inactivation pathway is oxidation, which is catalyzed by xanthine oxidase (XO) to form 6-thiouric acid.

The nucleotide diphosphatase (NUDT15) enzyme is involved in conversion of the 6-TGNs to inactive 6-TG monophosphates. TPMT activity correlates inversely with 6-TGN levels in erythrocytes and presumably other hematopoietic tissues, since these cells have negligible xanthine oxidase (involved in the other inactivation pathway) activities. Genetic polymorphisms influence TPMT and NUDT15 activity.

Several published studies indicate that patients with reduced TPMT or NUDT15 activity receiving usual doses of 6-MP or azathioprine, accumulate excessive cellular concentrations of active 6-TGNs, and are at higher risk for severe myelosuppression . Because of the risk of toxicity, patients with TPMT or NUDT15 deficiency require alternative therapy or dose modification (see DOSAGE AND ADMINISTRATION ). Approximately 0.3% (1:300) of patients of European or African ancestry have two loss-of-function alleles of the TPMT gene and have little or no TPMT activity (homozygous deficient or poor metabolizers), and approximately 10% of patients have one loss-of-function TPMT allele leading to intermediate TPMT activity (heterozygous deficient or intermediate metabolizers).

The TPMT*2, TPMT*3A, and TPMT*3C alleles account for about 95% of individuals with reduced levels of TPMT activity. NUDT15 deficiency is detected in <1% of patients of European or African ancestry. Among patients of East Asian ancestry (i.e., Chinese, Japanese, Vietnamese), 2% have two loss- of-function alleles of the NUDT15 gene, and approximately 21% have one loss-of-function allele.

The p.R139C variant of NUDT15 (present on the *2 and *3 alleles) is the most commonly observed, but other less common loss- of-function NUDT15 alleles have been observed. Inhibition of xanthine oxidase (XO) may cause increased plasma concentrations of azathioprine or its metabolites leading to toxicity (see PRECAUTIONS: Drug Interactions ). Proportions of metabolites are different in individual patients, and this presumably accounts for variable magnitude and duration of drug effects.

Renal clearance is probably not important in predicting biological effectiveness or toxicities, although dose reduction is practiced in patients with poor renal function. Homograft Survival The use of azathioprine…

📦 How Supplied / Storage and Handling 96 words

HOW SUPPLIED Azathioprine Sodium for Injection, USP, is supplied in a 20 mL vial, each containing azathioprine sodium, equivalent to 100 mg azathioprine. NDC 0143-9566-01. Store at 20° to 25°C (68° to 77°F) [See USP Controlled Room Temperature].

Protect from light. Retain in carton until time of use. The sterile, lyophilized sodium salt is yellow, and should be dissolved in Sterile Water for Injection (see DOSAGE AND ADMINISTRATION: Parenteral Administration ).

To report SUSPECTED ADVERSE REACTIONS, contact Hikma Pharmaceuticals USA Inc. at 1-877-845-0689, or the FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . For Product Inquiry call 1-877-845-0689.

📋 Description 187 words

DESCRIPTION Azathioprine Sodium for Injection, USP is a sterile lyophilized material, which when reconstituted with Sterile Water for Injection yields a solution for intravenous administration. Each vial contains azathioprine sodium equivalent to 100 mg azathioprine, an immunosuppressive antimetabolite. Each vial also contains sodium hydroxide and, if necessary, hydrochloric acid to adjust the pH.

Azathioprine is chemically 6-[(1-methyl-4-nitroimidazol-5-yl)thio]purine. The structural formula of azathioprine sodium is: Molecular Formula: C 9 H 7 N 7 O 2 SNa Molecular Weight: 300.28 It is an imidazolyl derivative of 6-mercaptopurine and many of its biological effects are similar to those of the parent compound. Azathioprine is insoluble in water, but may be dissolved with addition of one molar equivalent of alkali.

The sodium salt of azathioprine is sufficiently soluble to make a 10 mg/mL water solution which is stable for 24 hours at 59° to 77°F (15° to 25°C). Azathioprine is stable in solution at neutral or acid pH but hydrolysis to mercaptopurine occurs in excess sodium hydroxide (0.1N), especially on warming. Conversion to mercaptopurine also occurs in the presence of sulfhydryl compounds such as cysteine, glutathione and hydrogen sulfide.

Structural Formula

💬 Information for Patients 132 words

Information for Patients Patients being started on azathioprine should be informed of the necessity of periodic blood counts while they are receiving the drug and should be encouraged to report any unusual bleeding or bruising to their physician. They should be informed of the danger of infection while receiving azathioprine and asked to report signs and symptoms of infection to their physician. Careful dosage instructions should be given to the patient, especially when azathioprine is being administered in the presence of impaired renal function or concomitantly with allopurinol (see Drug Interactions subsection and DOSAGE AND ADMINISTRATION ).

Patients should be advised of the potential risks of the use of azathioprine during pregnancy and during the nursing period. The increased risk of malignancy following therapy with azathioprine should be explained to the patient.

Source: FDA Structured Product Labeling, mirrored from DailyMed / openFDA. Prefer the government’s original formatting? View this label on DailyMed ↗
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