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Mercaptopurine 50 mg Tablet, 250-count — NDC 71921-0150-25 package photo
Label image from the product's FDA listing (DailyMed) — may show a different pack size or an older label revision.

Mercaptopurine 50 mg Tablet, 250-count — NDC 71921-150-25 (Billing 71921-0150-25)

by Florida Pharmaceutical Products, LLC · 250 TABLET in 1 BOTTLE

This is a package of 250 tablets of Mercaptopurine 50 mg Tablet from Florida Pharmaceutical Products, LLC, marketed since Jan 2026 and currently FDA-listed; retail pharmacies pay about $1.07 per tablet (NADAC).

NDC 71921-0150-25
🏷️ FDA NDC (as labeled) 71921-150-25 billing pads the product segment with a zero
This package
Contains250-count Cost per ea$1.07 NADAC Per package$267.85 / 250 tablets Pack sizes2 compare ↓
Also priced by: Part D plans $1.77/unit — full pricing hub ↓
Product page 71921-0150-02 Also comes in: 25 tablets 71921-150-02
Rx only Brand On market Non-controlled ⇄ Compare with another NDC
🗂️ FDA directory synced Oct 1, 2026 · this listing last changed Jul 24, 2026 · sources: openFDA · FDA label (DailyMed) · FDA Orange & Purple Book · First Databank · CMS NADAC, ASP, Medicare & Medicaid · RxNorm
📋 All sources & update times →

This page is curated, coded, and maintained by

Compiled from public FDA, CMS, DailyMed, NADAC, and related drug data sources. Editorial policy

NDC database record

One package, one record: these facts belong to NDC 71921-150-25 alone.

Record
FDA NDC Directory package listing · Human prescription drug
Code segments
71921 labeler · 150 product · 25 package
Package marketed since
Jan 30, 2026
Sample package
No — commercial package
Listing certified through
Dec 31, 2027
Billing quantity
250 EA per package
Barcode (UPC)
0371921150250, 0371921150021
FDA record last changed
Jul 24, 2026

Identity & classification

Regulatory identifiers FDA, NLM and CMS codes for this package

FDA NDC (as labeled) 71921-150-25
Product NDC 71921-150
11-digit billing NDC 71921015025
NCPDP billing unit EA — each (per item)
RxCUI 197931
UNII E7WED276I5
UPC 0371921150250, 0371921150021
Application # NDA009053
SPL Set ID e7309808-5ae8-4a55-90e3-3992ace0da62
Established class (EPC) Nucleoside Metabolic Inhibitor
Mechanism of action Nucleic Acid Synthesis Inhibitors
DEA schedule Non-controlled
Marketing category NDA
Marketing status On market
FDA listing status Listed (active directory)
Marketing start 2026-01-30
Route ORAL
Dosage form TABLET
Substance MERCAPTOPURINE
TE code (Orange Book) AB · RLD · RS

Drug-database identifiers Medi-Span GPI and First Databank GCN / HICL / AHFS classification

GPI-14 21300040000305
GCN Seq No 008802
GCN 38520
HICL code 003908
Ingredient (HICL) Mercaptopurine
HIC1 code V
Therapeutic class — broad (HIC1) Neoplasms
HIC2 code V1
Therapeutic class — intermediate (HIC2) Antineoplastic Drugs
HIC3 code V1B
Therapeutic class — specific (HIC3) Antineoplastic - Antimetabolites
AHFS code 10:00.00.00
AHFS class Antineoplastic Agents
FDB label name MERCAPTOPURINE 50 MG TABLET
FDB brand name Mercaptopurine
Legend status F — Federal legend — prescription drug or device
Quick answers
  • GSN (GCN sequence number): 008802
  • GCN: 38520
  • GPI-14 (Medi-Span): 21300040000305
  • HICL (First Databank): 003908
  • AHFS class code: 10:00.00.00
  • RxCUI (RxNorm): 197931
Why two NDCs? The FDA registers this code as 71921-150-25 — a 5-3-2 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 product segment → 71921-0150-25. 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 Nucleoside Metabolic Inhibitor class.

Pharmacologic class Nucleoside Metabolic Inhibitor
Drug family (ATC) Purine analogues
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.

Clinical

Label name MERCAPTOPURINE 50 MG TABLET Ingredient Mercaptopurine
📗 Our plain-language guide HelloPharmacist
  • Mercaptopurine is a chemotherapy medicine used to help keep acute lymphoblastic leukemia (ALL) — a type of blood cancer — in remission. It's used during the maintenance phase of tr...
  • What exactly is mercaptopurine used for?
  • Either is fine, but you need to be consistent. Food reduces how much of the medicine your body absorbs, so if you always take it with a meal or always take it without food, your do...
  • Should I take this with food or on an empty stomach?
📖 Read our full Mercaptopurine guide →
1
Nutrient depletion considerations

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

🧪 Full Mercaptopurine nutrient depletion report →
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.

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 eaPer package
Retail pharmacies payNADAC · weekly $1.071 $267.85 / 250 tablets
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 · Q2 2026 $1.77 $441.43 / 250 tablets
NADAC price history (per ea) — tap or hover for the price & month
Aug 2026 Sep 2026 $1.071 $1.011
▲ Up 6% over the last 2 months.
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.

Packaging — all sizes for this product

Package NDCDescription Per unit Per pack Marketing startMarketing endStatus
71921-0150-02 71921-150-02 Main listing 25 TABLET in 1 BOTTLE $1.07 / ea $26.79 2026-01-30 — Active
71921-0150-25 You're viewing this 250 TABLET in 1 BOTTLE $1.07 / ea $267.86 2026-01-30 — Active

You're viewing the largest of 2 pack sizes for this product.

This pack effectively ties for the lowest per-ea cost of the 2 priced pack sizes ($1.07 NADAC).

Pack size FAQ

What quantity is in this package?
This is a 250-count package — 250 tablet in 1 bottle.
How does this package differ from NDC 71921-0150-02?
Both are Mercaptopurine 50 mg Tablet — the drug itself is identical. This page's package is the 250-count one, while NDC 71921-0150-02 is the 25 tablets package.
What NDC number is used to bill for this package of Mercaptopurine 50 mg Tablet?
Use the 11-digit billing form listed in the identifiers section of this page. Pharmacy and medical claims use the 11-digit form; the FDA label may print a shorter form of the same code.

Prices are the latest CMS NADAC pharmacy acquisition cost per NDC; per-pack figures are per-unit × pack quantity, shown only when the pack is denominated in the same measure NADAC prices.

Therapeutic equivalents

ProductLabelerPackNADAC/unitTEStatusPrice vs. this
Mercaptopurine 50 mg 00054-4581-11 Hikma 25 tablets $1.071 AB Availability likely —
Mercaptopurine 50 mgthis 71921-0150-25 Florida 250 tablets $1.071 AB Availability likely —
Mercaptopurine 50 mg 51407-0983-25 Golden 250 tablets — AB FDA listed —
About this product: this is the brand-name version. FDA-approved generic versions are listed, and recent pricing/market data suggests they may be available.
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

🏛️
2026
On the market since
Jan 2026
📍
2026
Currently FDA-listed
listed with the FDA
🔓
·
Generic versions listed
see equivalents
✅Generic appears available

FDA-approved generic versions are listed, and recent pricing/market data suggests they may be available — see Therapeutic equivalents.

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.

What it looks like

Color Yellow
ShapeRound
Size1 mm
ScoringNot scored
One label can cover several strengths, so colors may be combined — always confirm a loose pill against the dispensed prescription label or a pharmacist.
Where does this data come from?
Physical description (imprint, shape, color, scoring, coating) from this product’s FDA Structured Product Labeling (SPL), mirrored from DailyMed / openFDA.

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 EWQ57Q8I5X
    Lactose monohydrate is a natural sugar derived from milk. It serves as a filler and binder in tablets and capsules, helping create the proper size, texture, and consistency of the medicine.
  • UNII 70097M6I30
    Magnesium stearate is a salt made from magnesium and stearic acid, a fatty substance. It's used in tablets and capsules as a lubricant and glidant to help ingredients flow smoothly during manufacturing and prevent sticking.
  • UNII O8232NY3SJ
    A plant-based carbohydrate derived from corn kernels. It acts as a filler to add bulk, a binder to hold ingredients together, and a disintegrant to help the tablet break apart in your stomach for absorption.
  • UNII 8I089SAH3T
    A carbohydrate powder extracted from potatoes. It serves as a filler to add bulk and volume to the tablet or capsule, and as a disintegrant to help the medicine break apart and release its active ingredient in your body.
  • UNII 4ELV7Z65AP
    Stearic acid is a fatty acid derived from plant or animal sources. It acts as a binder and lubricant in tablets and capsules, helping them hold together and flow smoothly during manufacturing.
  • UNII 059QF0KO0R
    Water is a liquid solvent that dissolves and mixes ingredients together in liquid medicines, syrups, and injections. It helps distribute the active drug evenly throughout the product.

6 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 DailyMed — ingredient 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.

Manufacturer & labeler

LabelerFlorida Pharmaceutical Products, LLC
Application holderSTASON PHARMACEUTICALS INC
FDA applicationNDA009053 (NDA)
Labeler code71921
First marketedJan 2026
Product typeHuman Prescription Drug
Portfolio42 products on file

More NDCs from Florida Pharmaceutical Products, LLC labeler code 71921

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.

Full prescribing information FDA SPL

The complete FDA label for this product — the official prescribing information, verbatim, section by section. Very long sections are excerpted here and marked; the full text is on DailyMed (linked in the sources below). Jump with a chip, search within the label, or expand everything.
🎯 Indications and Usage ⏱️ Dosage and Administration 💊 Dosage Forms and Strengths ⛔ Contraindications ⚠️ Warnings and Cautions 🤒 Adverse Reactions 🔄 Drug Interactions 👥 Use in Specific Populations 🤰 Pregnancy 🧒 Pediatric Use 🧓 Geriatric Use 🆘 Overdosage 🧬 Clinical Pharmacology 🧬 Mechanism of Action 📦 How Supplied / Storage and Handling 📋 Description 💬 Information for Patients 🍼 Nursing Mothers 🧬 Pharmacokinetics 🧬 Pharmacodynamics 🧪 Nonclinical Toxicology 📄 Carcinogenesis, Mutagenesis, Impairment of Fertility 📚 References 📄 Recent Major Changes 📄 Package Label / Principal Display Panel
🎯 Indications and Usage 61 words ▾

1 INDICATIONS & USAGE Mercaptopurine tablets is a nucleoside metabolic inhibitor indicated for treatment of adult and pediatric patients with acute lymphoblastic leukemia (ALL) as part of a combination chemotherapy maintenance regimen. (1.1)

1.1Acute Lymphoblastic Leukemia Mercaptopurine tablets are indicated for treatment of adult and pediatric patients with acute lymphoblastic leukemia (ALL) as part of a combination chemotherapy maintenance regimen.

⏱️ Dosage and Administration ~2 min read ▾

2 DOSAGE & ADMINISTRATION The recommended starting dose of mercaptopurine tablets is 1.5 mg/kg to 2.5 mg/kg orally once daily as part of a combination chemotherapy maintenance regimen. Adjust dose to maintain desirable absolute neutrophil count and for excessive myelosuppression. (2.1) Renal Impairment : Use the lowest recommended starting dose or increase the dosing interval.

(2.3, 8.6) Hepatic Impairment : Use the lowest recommended starting dose. (2.3, 8.7)

2.1Recommended Dosage The recommended starting dosage of mercaptopurine tablets is 1.5 mg/kg to 2.5 mg/kg orally once daily as part of combination chemotherapy maintenance regimen. A recommended dosage for patients less than 17 kg is not achievable, because the only available strength is 50 mg. Take mercaptopurine tablets either consistently with or without food.

After initiating mercaptopurine tablets, monitor complete blood count (CBC) and adjust the dose to maintain absolute neutrophil count (ANC) at a desirable level and for excessive myelosuppression. Evaluate the bone marrow in patients with prolonged myelosuppression or repeated episodes of myelosuppression to assess leukemia status and marrow cellularity. Evaluate thiopurine S-methyltransferase (TPMT) and nucleotide diphosphatase (NUDT15) status in patients with severe myelosuppression or repeated episodes or myelosuppression [see Dosage and Administration (2.2)] .

Do not administer to patients who are unable to swallow tablets. If a patient misses a dose, instruct the patient to continue with the next scheduled dose. Mercaptopurine tablets is a cytotoxic drug.

Follow special handling and disposal procedures.

2.2Dosage Modifications in Patients with TPMT and NUDT15 Deficiency Consider testing for TPMT and NUDT15 deficiency in patients who experience severe myelosuppression or repeated episodes of myelosuppression [see Warnings and Precautions (5.1), Clinical Pharmacology (12.5)] . Homozygous Deficiency in either TPMT or NUDT15 Patients with homozygous deficiency of either enzyme typically require 10% or less of the recommended dosage. Reduce the recommended starting dosage of mercaptopurine tablets in patients who are known to have homozygous TPMT or NUDT15 deficiency.

Heterozygous Deficiency in TPMT and/or NUDT15 Reduce the mercaptopurine tablets dose based on tolerability. Most patients with heterozygous TPMT or NUDT15 deficiency tolerate the recommended dosage, but some require a dose reduction based on adverse reactions. Patients who are heterozygous for both TPMT and NUDT15 may require more substantial dose reductions.

2.3Dosage Modifications in Renal and Hepatic Impairment Renal Impairment Use the lowest recommended starting dosage for mercaptopurine tablets in patients with renal impairment (CLcr less than 50 mL/min). Adjust the dosage to maintain absolute neutrophil count (ANC) at a desirable level and for adverse reactions [see Uses in Specific Populations (8.6)] . Hepatic Impairment Use the lowest recommended starting dosage for mercaptopurine tablets in patients with hepatic impairment.

Adjust the dosage to maintain absolute neutrophil count (ANC) at a desirable level and for adverse reactions [see Uses in Specific Populations (8.7)] .

2.4Dosage Modification with Concomitant Use of Allopurinol Reduce the dose of mercaptopurine tablets to one-third to one-quarter of the current dosage when coadministered with allopurinol [see Drug Interactions (7.1)] .

💊 Dosage Forms and Strengths 24 words ▾

3 DOSAGE FORMS & STRENGTHS Tablets: 50 mg mercaptopurine, biconvex, round, pale yellow to buff, scored tablets imprinted with “9|3” Tablets: 50 mg (3)

⛔ Contraindications 4 words ▾

4 CONTRAINDICATIONS None. None.

⚠️ Warnings and Cautions ~2 min read ▾

5 WARNINGS AND PRECAUTIONS Myelosuppression : Monitor complete blood count (CBC) and adjust the dose of mercaptopurine tablets for excessive myelosuppression. Consider testing in patients with severe myelosuppression or repeated episodes of myelosuppression for thiopurine S -methyltransferase (TPMT) or nucleotide diphosphatase (NUDT15) deficiency. Patients with homozygous or homozygous TPMT or NUDT15 deficiency may require a dose reduction.

(2.2, 5.1) Hepatotoxicity : Monitor transaminases, alkaline phosphatase and bilirubin. Withhold mercaptopurine tablets at onset of hepatotoxicity. (5.2) Immunosuppression : Response to all vaccines may be diminished and there is a risk of infection with live virus vaccines.

Consult immunization guidelines for immunocompromised patients. (5.3) Treatment Related Malignancies : Aggressive and fatal cases of hepatosplenic T-cell lymphoma have occurred. (5.4) Macrophage Activation Syndrome : Monitor for and treat promptly; discontinue mercaptopurine tablets.

(5.5) Embryo-Fetal Toxicity : Can cause fetal harm. Advise patients of reproductive potential of the potential risk to a fetus and to use effective contraception. (5.6, 8.1, 8.3)

5.1Myelosuppression The most consistent, dose-related adverse reaction is myelosuppression, manifested by anemia, leukopenia, thrombocytopenia, or any combination of these. Monitor CBC and adjust the dosage of mercaptopurine tablets for excessive myelosuppression [see Dosage and Administration (2.1)] . Consider testing for TPMT or NUDT15 deficiency in patients with severe myelosuppression or repeated episodes of myelosuppression.

TPMT genotyping or phenotyping (red blood cell TPMT activity) and NUDT15 genotyping can identify patients who have reduced activity of these enzymes. Patients with heterozygous or homozygous TPMT or NUDT15 deficiency may require a dose reduction [see Dosage and Administration (2.2), Clinical Pharmacology (12.5)] . Myelosuppression can be exacerbated by coadministration with allopurinol, aminosalicylates or other products that cause myelosuppression [see Drug Interactions (7.1, 7.3, 7.4)].

Reduce the dose of mercaptopurine tablets when coadministered with allopurinol [see Dosage and Administration (2.4)] .

5.2Hepatoxicity Mercaptopurine is hepatotoxic. There are reports of deaths attributed to hepatic necrosis associated with the administration of mercaptopurine. Hepatic injury can occur with any dosage but seems to occur with greater frequency when the recommended dosage is exceeded.

In some patients, jaundice has cleared following withdrawal of mercaptopurine and reappeared with rechallenge. Usually, clinically detectable jaundice appears early in the course of treatment (1 to 2 months); however, jaundice has been reported as early as 1 week and as late as 8 years after the starting mercaptopurine. The hepatotoxicity has been associated in some cases with anorexia, diarrhea, jaundice, ascites, and pruritus.

Hepatic encephalopathy has occurred. Monitor serum transaminase levels, alkaline phosphatase, and bilirubin levels at weekly intervals when first beginning therapy and at monthly intervals thereafter. Monitor liver tests more frequently in patients who are receiving mercaptopurine tablets with other hepatotoxic products [see Drug Interactions (7.5)] or with known pre-existing liver disease.

Withhold mercaptopurine tablets at onset of hepatotoxicity. Intrahepatic Cholestasis of Pregnancy Postmarketing cases of intrahepatic cholestasis of pregnancy (ICP) have been reported in patients with inflammatory bowel disease who received mercaptopurine during pregnancy. Mercaptopurine is not indicated for use in inflammatory bowel disease [see Indications and Usage (1.1)] .

Discontinue Mercaptopurine if ICP develops in a pregnant woman.

5.3Immunosuppression Mercaptopurine is immunosuppressive and may impair the immune response to infectious agents or vaccines. Due to the immunosuppression associated with maintenance chemotherapy for ALL, respon… [Excerpted — this section continues on DailyMed.]

🤒 Adverse Reactions ~1 min read ▾

6 ADVERSE REACTIONS The following clinically significant adverse reactions are described elsewhere in the labeling: Myelosuppression [see Warnings and Precautions (5.1)] Hepatotoxicity [see Warnings and Precautions (5.2)] Immunosuppression [see Warnings and Precautions (5.3)] Treatment related malignancies [see Warnings and Precautions (5.4)] Macrophage activation syndrome [see Warnings and Precautions (5.5)] The most common adverse reaction (>20%) is myelosuppression, including anemia, leukopenia and thrombocytopenia.

Adverse reactions occurring in 5% to 20% of patients include anorexia, nausea, vomiting, diarrhea, malaise and rash. (6.1) To report SUSPECTED ADVERSE REACTIONS, contact Florida Pharmaceutical Products, LLC at 1-800-315-0985 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch

6.1Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Based on multicenter cooperative group ALL trials, the most common adverse reaction occurring in > 20% of patients was myelosuppression, including anemia, neutropenia, lymphopenia and thrombocytopenia. Adverse reactions occurring in 5% to 20% of patients included anorexia, nausea, vomiting, diarrhea, malaise and rash.

Adverse reactions occurring in < 5 % of patients included urticaria, hyperuricemia, oral lesions, increased transaminases, hyperbilirubinemia, hyperpigmentation, infections, and pancreatitis. Oral lesions resemble thrush rather than antifolic ulcerations. Delayed or late adverse reactions include hepatic fibrosis, hyperbilirubinemia, alopecia, pulmonary fibrosis, oligospermia and secondary malignancies [see Warnings and Precautions (5.1, 5.2)].

Drug fever has been reported with mercaptopurine. Additional adverse reactions that have been reported in patients who have received mercaptopurine include photosensitivity, hypoglycemia, and portal hypertension.

6.2Postmarketing Experience The following adverse reactions have been identified during postapproval use of mercaptopurine tablets. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. These reactions include: intrahepatic cholestasis of pregnancy (ICP).

🔄 Drug Interactions ~1 min read ▾

7 DRUG INTERACTIONS Allopurinol : Reduce the dose of mercaptopurine tablets when co-administered with allopurinol. (2.4, 7.1) Warfarin : Mercaptopurine tablets may decrease the anticoagulant effect. (7.2)

7.1Allopurinol Allopurinol can inhibit the first-pass oxidative metabolism of mercaptopurine by xanthine oxidase, which can lead to an increased risk of mercaptopurine adverse reactions (i.e., myelosuppression, nausea, and vomiting) [see Warnings and Precautions (5.1), Adverse Reactions (6.1)] . Reduce the dose of mercaptopurine tablets when coadministered with allopurinol [see Dosage and Administration (2.4)] .

7.2Warfarin The concomitant administration of mercaptopurine tablets and warfarin may decrease the anticoagulant effectiveness of warfarin. Monitor the international normalized ratio (INR) in patients receiving warfarin and adjust the warfarin dosage as appropriate.

7.3Myelosuppresive Products Mercaptopurine tablets can cause myelosuppression. Myelosuppression may be increased when mercaptopurine tablets is coadministered with other products that cause myelosuppression. Enhanced myelosuppression has been noted in some patients also receiving trimethoprim-sulfamethoxazole.

Monitor the CBC and adjust the dose of mercaptopurine tablets for excessive myelosuppression [see Dosage and Administration (2.1), Warnings and Precautions (5.1)] .

7.4Aminosalicylates Aminosalicylates (e.g., mesalamine, olsalazine or sulfasalazine) may inhibit the TPMT enzyme, which may increase the risk of myelosuppression when coadministered with mercaptopurine tablets. When aminosalicylates and mercaptopurine tablets are coadministered, use the lowest possible doses for each drug and monitor more frequently for myelosuppression [see Warnings and Precautions (5.1)] .

7.5Hepatotoxic Products Mercaptopurine tablets can cause hepatotoxicity. Hepatotoxicity may be increased when mercaptopurine tablets is coadministered with other products that cause hepatotoxicity. Monitor liver tests more frequently in patients who are receiving mercaptopurine tablets with other hepatotoxic products [see Warnings and Precautions (5.2)] .

👥 Use in Specific Populations ~3 min read ▾

8 USE IN SPECIFIC POPULATIONS Lactation : Advise not to breastfeed. (8.2) Infertility : Can impair fertility. (8.3)

8.1Pregnancy Risk Summary Mercaptopurine tablets can cause fetal harm when administered to a pregnant woman [see Clinical Pharmacology (12.1)] . Pregnant women who receive mercaptopurine have an increased incidence of miscarriage and stillbirth ( see Data ). Advise pregnant women of the potential risk to a fetus.

The estimated background risk of major birth defects and miscarriage for the indicated population(s) is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.

Data Human Data Women receiving mercaptopurine in the first trimester of pregnancy have an increased incidence of miscarriage; the risk of malformation in offspring surviving first trimester exposure is not known. In a series of 28 women receiving mercaptopurine after the first trimester of pregnancy, 3 mothers died prior to delivery, 1 delivered a stillborn child, and 1 aborted; there were no cases of macroscopically abnormal fetuses. Animal Data Mercaptopurine was embryo-lethal and teratogenic in several animal species (rat, mouse, rabbit, and hamster) at doses less than the recommended human dose.

8.2Lactation Risk Summary There are no data on the presence of mercaptopurine or its metabolites in human milk, the effects on the breastfed child, or the effects on milk production. Because of the potential for serious adverse reactions in the breastfed child, advise women not to breastfeed during treatment with mercaptopurine tablets and for 1 week after the last dose.

8.3Females and Males of Reproductive Potential Mercaptopurine tablets can cause fetal harm when administered to pregnant women [see Use in Specific Populations (8.1)] . Pregnancy Testing Verify the pregnancy status in females of reproductive potential prior to initiating mercaptopurine tablets [see Use in Specific Populations (8.1)] . Contraception Females Advise females of reproductive potential to use effective contraception during treatment with mercaptopurine tablets and for 6 months after the last dose.

Males Based on genotoxicity findings, advise males with female partners of reproductive potential to use effective contraception during treatment with mercaptopurine tablets and for 3 months after the last dose [see Nonclinical Toxicology (13.1)] . Infertility Females and Males Based on findings from animal studies, mercaptopurine tablets can impair female and male fertility [see Nonclinical Toxicology (13.1)] . The long-term effects of mercaptopurine on female and male fertility, including the reversibility have not been studied.

8.4Pediatric Use Safety and effectiveness of mercaptopurine tablets has been established in pediatric patients. Use of mercaptopurine tablets in pediatrics is supported by evidence from the published literature and clinical experience. Symptomatic hypoglycemia has been reported in pediatric patients with ALL receiving mercaptopurine. Reported cases were in pediatrics less than 6 years of age or with a low body mass index.

8.5Geriatric Use Clinical studies of mercaptopurine did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or another drug therapy.

8.6Renal Impairment Use the lowest recommended starting dosage for mercaptopurine tablets or increase the dosing interval to every 36-48 hours in patients wit… [Excerpted — this section continues on DailyMed.]

🤰 Pregnancy 197 words ▾

8.1Pregnancy Risk Summary Mercaptopurine tablets can cause fetal harm when administered to a pregnant woman [see Clinical Pharmacology (12.1)] . Pregnant women who receive mercaptopurine have an increased incidence of miscarriage and stillbirth ( see Data ). Advise pregnant women of the potential risk to a fetus.

The estimated background risk of major birth defects and miscarriage for the indicated population(s) is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.

Data Human Data Women receiving mercaptopurine in the first trimester of pregnancy have an increased incidence of miscarriage; the risk of malformation in offspring surviving first trimester exposure is not known. In a series of 28 women receiving mercaptopurine after the first trimester of pregnancy, 3 mothers died prior to delivery, 1 delivered a stillborn child, and 1 aborted; there were no cases of macroscopically abnormal fetuses. Animal Data Mercaptopurine was embryo-lethal and teratogenic in several animal species (rat, mouse, rabbit, and hamster) at doses less than the recommended human dose.

🧒 Pediatric Use 62 words ▾

8.4Pediatric Use Safety and effectiveness of mercaptopurine tablets has been established in pediatric patients. Use of mercaptopurine tablets in pediatrics is supported by evidence from the published literature and clinical experience. Symptomatic hypoglycemia has been reported in pediatric patients with ALL receiving mercaptopurine. Reported cases were in pediatrics less than 6 years of age or with a low body mass index.

🧓 Geriatric Use 83 words ▾

8.5Geriatric Use Clinical studies of mercaptopurine did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or another drug therapy.

🆘 Overdosage 82 words ▾

10 OVERDOSAGE Signs and symptoms of mercaptopurine overdosage may be immediate (anorexia, nausea, vomiting, and diarrhea); or delayed (myelosuppression, liver dysfunction, and gastroenteritis). Dialysis cannot be expected to clear mercaptopurine. Hemodialysis is thought to be of marginal use due to the rapid intracellular incorporation of mercaptopurine into active metabolites with long persistence.

Withhold mercaptopurine tablets immediately for severe or life-threatening adverse reactions occur during treatment. If a patient is seen immediately following an accidental overdosage, it may be useful to induce emesis.

🧬 Clinical Pharmacology ~3 min read ▾

12 CLINICAL PHARMACOLOGY

12.1Mechanism of Action Mercaptopurine is a purine analog that undergoes intracellular transport and activation to form metabolites including thioguanine nucleotides (TGNs). Incorporation of TGNs into DNA or RNA results in cell-cycle arrest and cell death. TGNs and other mercaptopurine metabolites are also inhibitors of de novo purine synthesis and purine nucleotide interconversions.

Mercaptopurine was cytotoxic to proliferating cancer cells in vitro and had antitumor activity in mouse tumor models. It is not known which of the biochemical effects of mercaptopurine and its metabolites are directly or predominantly responsible for cell death.

12.2Pharmacodynamics Exposure-Response Relationships Mercaptopurine exposure-response relationships and the time course of pharmacodynamics response are unknown.

12.3Pharmacokinetics Following a single oral dose of mercaptopurine 50 mg under fasted conditions to adult healthy subjects, the mean AUC 0-INF was 129 h·ng/mL and C max was 69 ng/mL. Absorption Food Effect Food has been shown to decrease the exposure of mercaptopurine. Distribution The volume of distribution usually exceeded that of the total body water.

There is negligible entry of mercaptopurine into cerebrospinal fluid. Plasma protein binding averages 19% over the concentration range 10 to 50 mcg/mL (a concentration only achieved by intravenous administration of mercaptopurine at doses exceeding 5 to 10 mg/kg). Elimination The elimination half-life is less than 2 hours following a single oral dose.

Metabolism Mercaptopurine is inactivated via two major pathways. One is thiol methylation, which is catalyzed by the polymorphic enzyme thiopurine S-methyltransferase (TPMT), to form the inactive metabolite methyl-mercaptopurine. The second inactivation pathway is oxidation, which is catalyzed by xanthine oxidase.

The product of oxidation is the inactive metabolite 6-thiouric acid. Excretion Following the oral administration of radiolabeled mercaptopurine, 46% of the dose was recovered in the urine (as parent drug and metabolites) in the first 24 hours.

12.5Pharmacogenomics Several published studies indicate that patients with reduced TPMT or NUDT15 activity receiving usual doses of mercaptopurine, accumulate excessive cellular concentrations of active 6-TGNs, and are at higher risk for severe myelosuppression. In a study of 1028 children with ALL, the approximate tolerated mercaptopurine dosage for patients with TPMT and/or NUDT15 deficiency on mercaptopurine maintenance therapy (as a percentage of the planned dosage) was as follows: heterozygous for either TPMT or NUDT15, 50-90%; heterozygous for both TPMT and NUDT15, 30-50%; homozygous for either TPMT or NUDT15, 5-10%.

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. Consider all clinical information when interpreting results from phenotypic testing used to determine the level of thiopurine nucleotides or TPMT activity in erythrocytes, since some coadministered drugs can influence measurement of TPMT activity in blood and blood from recent transfusions will misrepresent a patient’s actual TP… [Excerpted — this section continues on DailyMed.]

🧬 Mechanism of Action 92 words ▾

12.1Mechanism of Action Mercaptopurine is a purine analog that undergoes intracellular transport and activation to form metabolites including thioguanine nucleotides (TGNs). Incorporation of TGNs into DNA or RNA results in cell-cycle arrest and cell death. TGNs and other mercaptopurine metabolites are also inhibitors of de novo purine synthesis and purine nucleotide interconversions.

Mercaptopurine was cytotoxic to proliferating cancer cells in vitro and had antitumor activity in mouse tumor models. It is not known which of the biochemical effects of mercaptopurine and its metabolites are directly or predominantly responsible for cell death.

📦 How Supplied / Storage and Handling 85 words ▾

16 HOW SUPPLIED/STORAGE AND HANDLING Mercaptopurine tablets are supplied as biconvex, round, pale yellow to buff, scored tablets containing 50 mg mercaptopurine, imprinted with “9|3” available in: bottles of 25 NDC 71921-150-02 bottles of 250 NDC 71921-150-25 Store at 20°C to 25°C (68°F to 77°F); excursions permitted to 15°C to 30°C (59°F to 86°F) [see USP Controlled Room Temperature]. Store in a dry place. Dispense in tight container as defined in the USP.

Mercaptopurine tablets is a cytotoxic drug. Follow special handling and disposal procedures.

📋 Description 113 words ▾

11 DESCRIPTION Mercaptopurine is a nucleoside metabolic inhibitor, the chemical name is 6H-purine-6-thione, 1,7-dihydro-, monohydrate. The molecular formula is C 5 H 4 N 4 S • H 2 O and the molecular weight is 170.20. Its structural formula is: Mercaptopurine is a yellow, crystalline powder.

Mercaptopurine is practically insoluble in water and in ether. It has a pKa of 7.8, an average tapped density of 1.0 g/mL and average bulk density of 0.85 g/mL. It dissolves in solutions of alkali hydroxides.

Mercaptopurine tablets is available for oral use. Each scored tablet contains 50 mg mercaptopurine and the following inactive ingredients: corn starch, pregelatinized, potato starch, lactose, magnesium stearate and stearic acid. Mercaptopurine-Structure

💬 Information for Patients ~1 min read ▾

17 PATIENT COUNSELING INFORMATION Major Adverse Reactions Advise patients and caregivers that mercaptopurine tablets can cause myelosuppression, hepatotoxicity, and gastrointestinal toxicity. Advise patients to contact their healthcare provider if they experience fever, sore throat, jaundice, nausea, vomiting, signs of local infection, bleeding from any site, or symptoms suggestive of anemia [see Warnings and Precautions (5.1, 5.2, 5.3)] . Embryo-Fetal Toxicity Advise pregnant women of the potential risk to a fetus.

Advise females of reproductive potential to inform their healthcare provider of a known or suspected pregnancy [see Warnings and Precautions (5.2, 5.6), Use in Specific Populations (8.1)] . Advise females of reproductive potential to use effective contraception during treatment with mercaptopurine tablets and for 6 months after the last dose [see Use in Specific Populations (8.3)] . Advise males with female partners of reproductive potential to use effective contraception during treatment with mercaptopurine tablets and for 3 months after the last dose [see Use in Specific Populations (8.3), Nonclinical Toxicology (13.1)] .

Lactation Advise women not to breastfeed during treatment with mercaptopurine tablets and for 1 week after the last dose [see Use in Specific Populations (8.2)] . Infertility Advise males and females of reproductive potential that mercaptopurine tablets can impair fertility [see Use in Specific Populations (8.3)] . Other Adverse Reactions Instruct patients to minimize sun exposure due to risk of photosensitivity [see Adverse Reactions (6.1)] .

Manufactured By: Pinnacle Life Science Pvt. Ltd. Baddi, Solan, HP174101, India Manufactured For: Florida Pharmaceutical Products, LLC Boca Raton, FL 33487 Toll-Free # 1-800-315-0985

🍼 Nursing Mothers 147 words ▾

8.3Females and Males of Reproductive Potential Mercaptopurine tablets can cause fetal harm when administered to pregnant women [see Use in Specific Populations (8.1)] . Pregnancy Testing Verify the pregnancy status in females of reproductive potential prior to initiating mercaptopurine tablets [see Use in Specific Populations (8.1)] . Contraception Females Advise females of reproductive potential to use effective contraception during treatment with mercaptopurine tablets and for 6 months after the last dose.

Males Based on genotoxicity findings, advise males with female partners of reproductive potential to use effective contraception during treatment with mercaptopurine tablets and for 3 months after the last dose [see Nonclinical Toxicology (13.1)] . Infertility Females and Males Based on findings from animal studies, mercaptopurine tablets can impair female and male fertility [see Nonclinical Toxicology (13.1)] . The long-term effects of mercaptopurine on female and male fertility, including the reversibility have not been studied.

🧬 Pharmacokinetics 186 words ▾

12.3Pharmacokinetics Following a single oral dose of mercaptopurine 50 mg under fasted conditions to adult healthy subjects, the mean AUC 0-INF was 129 h·ng/mL and C max was 69 ng/mL. Absorption Food Effect Food has been shown to decrease the exposure of mercaptopurine. Distribution The volume of distribution usually exceeded that of the total body water.

There is negligible entry of mercaptopurine into cerebrospinal fluid. Plasma protein binding averages 19% over the concentration range 10 to 50 mcg/mL (a concentration only achieved by intravenous administration of mercaptopurine at doses exceeding 5 to 10 mg/kg). Elimination The elimination half-life is less than 2 hours following a single oral dose.

Metabolism Mercaptopurine is inactivated via two major pathways. One is thiol methylation, which is catalyzed by the polymorphic enzyme thiopurine S-methyltransferase (TPMT), to form the inactive metabolite methyl-mercaptopurine. The second inactivation pathway is oxidation, which is catalyzed by xanthine oxidase.

The product of oxidation is the inactive metabolite 6-thiouric acid. Excretion Following the oral administration of radiolabeled mercaptopurine, 46% of the dose was recovered in the urine (as parent drug and metabolites) in the first 24 hours.

🧬 Pharmacodynamics 16 words ▾

12.2Pharmacodynamics Exposure-Response Relationships Mercaptopurine exposure-response relationships and the time course of pharmacodynamics response are unknown.

🧪 Nonclinical Toxicology 78 words ▾

13 NONCLINICAL TOXICOLOGY

13.1Carcinogenesis & Mutagenesis & Impairment Of Fertility Mercaptopurine is carcinogenic in animals. Mercaptopurine causes chromosomal aberrations in cells derived from animals and humans and induces dominant-lethal mutations in the germ cells of male mice. Mercaptopurine can impair fertility.

In mice, surviving female offspring of mothers who received chronic low doses of mercaptopurine during pregnancy were found sterile, or if they became pregnant, had smaller litters and more dead fetuses as compared to control animals.

📄 Carcinogenesis, Mutagenesis, Impairment of Fertility 75 words ▾

13.1Carcinogenesis & Mutagenesis & Impairment Of Fertility Mercaptopurine is carcinogenic in animals. Mercaptopurine causes chromosomal aberrations in cells derived from animals and humans and induces dominant-lethal mutations in the germ cells of male mice. Mercaptopurine can impair fertility.

In mice, surviving female offspring of mothers who received chronic low doses of mercaptopurine during pregnancy were found sterile, or if they became pregnant, had smaller litters and more dead fetuses as compared to control animals.

📚 References 8 words ▾

15 REFERENCES 1. OSHA Hazardous Drugs. OSHA. http://www.osha.gov/SLTC/hazardousdrugs/index.html

📄 Recent Major Changes 6 words ▾

Warnings and Precautions, Hepatotoxicity (5.2) 07/2024

📄 Package Label / Principal Display Panel 22 words ▾

PACKAGE LABEL.PRINCIPAL DISPLAY PANEL Mercaptopurine tablets Container Label 25 Tablets NDC 71921-150-02 Mercaptopurine tablets Container Label 250 Tablets NDC 71921-150-25 Mercaptopurine-Container-2 Mercaptopurine-Container-1

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

Medicare Part D spend CMS · PART D · 2026 (Q1)

Medicare Part D (outpatient prescription) spending for Mercaptopurine — the program that covers self-administered drugs. 2 manufacturers.
⚠️ Drug-level data: CMS publishes Part D spending by drug, not by NDC — these figures combine every manufacturer, strength and package size sold under the name Mercaptopurine. That’s a different level of aggregation than the Medicaid card above, which is specific to this exact 11-digit NDC (pack size included), so the two aren’t directly comparable.
Period
Total Part D spend
$1.12M
Claims incl. refills
8.9K
Beneficiaries
6.5K
Spend / beneficiary
$173.07
Spend / claim
$125.65
Trend by period
💵 About the dollar figures: spending is what Part D plans paid before confidential manufacturer rebates, so the program’s real net cost is lower. A blank patient count means fewer than 11 people — CMS hides counts that small to protect privacy. Source: CMS Medicare Quarterly Part D Spending by Drug (data.cms.gov), updated quarterly.
← 71921-0146-01 · Florida 71921-0162-01 · Florida →
For educational and professional reference only — not medical advice. Pricing reflects published NADAC and CMS ASP (free public data) and may differ from your acquisition cost; always verify before billing or dispensing.