MERCAPTOPURINE

MERCAPTOPURINE is an FDA-registered drug product whose active ingredient is MERCAPTOPURINE. It is labelled by Hikma Pharmaceuticals USA Inc. taken by oral and marketed as a human prescription drug product. Identifiers on file: NDC 0054-0879, application ANDA216418, label effective 20260722. It is one of 2 FDA drug label records sharing the active ingredient MERCAPTOPURINE. This page reproduces the FDA-approved label text so you can check what a product is, who makes it and how it is supplied before discussing it with a pharmacist or prescriber.

Across FDA labelling, products containing MERCAPTOPURINE are most often described in connection with: acute lymphoblastic, treatment patients, part combination, chemotherapy maintenance, usage mercaptopurine, nucleoside metabolic, inhibitor indicated. Wording differs between labels, and the full indications section on this page takes precedence when it is present.

1 INDICATIONS AND USAGE Mercaptopurine is a nucleoside metabolic inhibitor indicated for the treatment of patients with acute lymphoblastic leukemia (ALL) as part of a combination chemotherapy maintenance regimen. ( 1.1 ) 1.1 Acute Lymphoblastic Leukemia Mercaptopurine is indicated for the treatment of patients with acute lymphoblastic leukemia (ALL) as part of a combination chemotherapy maintenance regimen.

2 DOSAGE AND ADMINISTRATION • The recommended starting dosage of mercaptopurine oral suspension is 1.5 mg/kg to 2.5 mg/kg (50 mg/m 2 to 75 mg/m 2 ) 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 ) 2.1 Recommended Dosage The recommended starting dose of mercaptopurine oral suspension is 1.5 mg/kg to 2.5 mg/kg (50 mg/m 2 to 75 mg/m 2 ) orally once daily as part of combination chemotherapy maintenance regimen. Take mercaptopurine oral suspension either consistently with or without food [see Clinical Pharmacology ( 12.3 )] . After initiating mercaptopurine, monitor complete blood counts (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 of myelosuppression [see Dosage and Administration ( 2.2 )] . If a patient misses a dose, instruct the patient to continue with the next scheduled dose. 2.2 Dosage Modifications in Patients with TPMT and/or 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 in patients who are known to have homozygous TPMT or NUDT15 deficiency. Heterozygous Deficiency in TPMT and/or NUDT15 Reduce the mercaptopurine dosage based on tolerability. Most patients with heterozygous TPMT or NUDT15 deficiency tolerate recommended dosage, but some require dose reduction based on adverse reactions. Patients who are heterozygous for both TPMT and NUDT15 may require more substantial dose reductions. 2.3 Dosage Modifications in Renal and Hepatic Impairment Renal Impairment Use the lowest recommended starting dosage for mercaptopurine or increase the dosing interval to every 36 to 48 hours 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 Use in Specific Populations ( 8.6 )] . Hepatic Impairment Use the lowest recommended starting dosage for mercaptopurine in patients with hepatic impairment. Adjust the dosage to maintain absolute neutrophil count (ANC) at a desirable level and for adverse reactions [see Use in Specific Populations ( 8.7 )] . 2.4 Dosage Modification with Concomitant Use of Allopurinol Reduce the dose of mercaptopurine to one-third to one-quarter of the current dosage when coadministered with allopurinol [see Drug Interactions ( 7.1 )] . 2.5 Administration Shake the bottle vigorously for at least 30 seconds to ensure the oral suspension is well mixed. Mercaptopurine oral suspension is a pink to brown viscous oral suspension. Provide a press-in bottle adapter and two oral dispensing syringes (one 1 mL and one 5 mL). Train patients or caregivers on proper handling, storage, administration, disposal and clean-up of accidental spillage prior to initiation of mercaptopurine oral suspension and during each visit to the clinic. Advise patients and caregivers to use mercaptopurine oral suspension within 8 weeks and properly discard remaining mercaptopurine oral suspension after 8 weeks. Provide instructions regarding which syringe to use and how to administer the specified dose, since mercaptopurine oral suspension is supplied with 1 mL and 5 mL oral dispensing syringes. Advise patients that the oral dispensing syringe is intended for multiple uses and provide the following instructions: • Wash the oral dispensing syringe with warm ‘soapy’ water and rinse well; • Hold the oral dispensing syringe under water and move the plunger up and down several times to make sure the inside of the oral dispensing syringe is clean; • Ensure the oral dispensing syringe is completely dry before use of the oral dispensing syringe again; and • Store the oral dispensing syringe in a hygienic place with mercaptopurine oral suspension. Mercaptopurine is a hazardous drug. Follow special handling and disposal procedures. 1

4 CONTRAINDICATIONS None. • None

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, neutropenia, lymphopenia 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 Hikma Pharmaceuticals USA Inc. at 1-800-962-8364 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical 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, elevated transaminases, hyperbilirubinemia, hyperpigmentation, infections, and pancreatitis. Oral lesions resemble thrush rather than antifolic ulcerations. Delayed or late toxicities 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. 6.2 Postmarketing Experience The following adverse reactions have been identified during postapproval use of mercaptopurine. 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: photosensitivity, hypoglycemia, portal hypertension, intrahepatic cholestasis of pregnancy (ICP), pellagra, erythema nodosum, and mucosal inflammation.

FDA lists 2 drug label records with MERCAPTOPURINE as the active ingredient. The most common dosage forms and the manufacturers with the most records are summarised below; strengths, pack sizes and inactive ingredients can still differ between apparently similar products.

5 FDA recall record(s) match this product name or manufacturer. A match means the firm or product name appears in the enforcement report; confirm lot numbers and dates against the official FDA notice before acting.

What is MERCAPTOPURINE used for?
1 INDICATIONS AND USAGE Mercaptopurine is a nucleoside metabolic inhibitor indicated for the treatment of patients with acute lymphoblastic leukemia (ALL) as part of a combination chemotherapy maintenance regimen. ( 1.1 ) 1.1 Acute Lymphoblastic Leukemia Mercaptopurine is indicated for the treatment of patients with acute lymphoblastic leukemia (ALL) as part of a combination chemotherapy …

Who makes MERCAPTOPURINE?
Hikma Pharmaceuticals USA Inc. is the labeler of record for MERCAPTOPURINE. 2 FDA label records share the active ingredient MERCAPTOPURINE, so generic and branded versions may come from different companies; the manufacturer named on your pack is the one that matters for any enquiry.

What form does MERCAPTOPURINE come in?
administered by oral. Strengths and pack sizes vary by label, so compare the NDC on your pack with the identifier listed on this page.

Is MERCAPTOPURINE prescription or over-the-counter?
The FDA label for this product is recorded as human prescription drug. Marketing status can differ between strengths and countries, so check the dispensing rules where you live.

Are there other products containing MERCAPTOPURINE?
Yes. 2 FDA drug label records list MERCAPTOPURINE as the active ingredient. Products with the same active ingredient can usually be substituted only when a prescriber or pharmacist confirms it is appropriate.

Has MERCAPTOPURINE been recalled?
5 FDA recall record(s) match this product name or manufacturer. Review the recall and safety notices section on this page and confirm lot numbers against the official FDA enforcement report.

Where does this information come from?
All content is reproduced from FDA Structured Product Labelling data via openFDA. It is provided for identification and reference only and is not medical advice.