Mercaptopurine Dosage

Medically reviewed by Drugs.com. Last updated on Mar 15, 2024.

Applies to the following strengths: 50 mg; 100 mg/5 mL

Usual Adult Dose for Acute Lymphoblastic Leukemia

TABLETS:

MAINTENANCE THERAPY: When a complete hematologic remission is obtained, maintenance therapy is considered essential. Maintenance doses vary. The usual daily maintenance dose is 1.5 to 2.5 mg/kg/day orally as a single dose. This drug should rarely be relied upon as a single agent for the maintenance of remissions induced in acute leukemia.
DOSAGE WITH CONCOMITANT ALLOPURINOL: When this drug is given concomitantly with allopurinol, the dose of this drug should be reduced to one-third to one-quarter of the usual dose to avoid severe toxicity.

SUSPENSION:

MAINTENANCE THERAPY: The recommended starting dose of this drug in multi-agent combination chemotherapy maintenance regimens is 1.5 to 2.5 mg/kg (50 to 75 mg/m2) orally as a single daily dose.
HOMOZYGOUS DEFICIENCY IN EITHER TPMT OR NUDT15: Patients with homozygous deficiency of either enzyme typically require 10% or less of the standard oral suspension dose. Reduce initial dose in patients who are known to have homozygous TPMT or NUDT15 deficiency.
HETEROZYGOUS DEFICIENCY IN TPMT AND/OR NUDT15: Reduce the oral suspension dose based on tolerability. Most patients with heterozygous TPMT or NUDT15 deficiency tolerate recommended doses, but some require dose reduction based on toxicities. Patients who are heterozygous for both TPMT and NUDT15 may require more substantial dosage reductions.

Comments:

The dosage recommendations presented here are manufacturer suggested; consult local institutional guidelines for alternate dosing options.
After initiating therapy, monitor complete blood counts (CBCs), transaminases, and bilirubin.
Maintain ANC at a desirable level by reducing the dose in patients with excessive hematological toxicity.
Evaluate the bone marrow in patients with prolonged or repeated marrow suppression to assess leukemia status and marrow cellularity.
Evaluate thiopurine S-methyltransferase (TPMT) and nucleotide diphosphatase (NUDT15) status in patients with clinical or laboratory evidence of severe bone marrow toxicity, or repeated episodes of myelosuppression.
There is no general agreement that the procedures recommended in the guidelines are necessary or appropriate.

Use:

Tablets: For maintenance therapy of acute lymphatic (lymphocytic, lymphoblastic) leukemia as part of a combination regimen; response to this agent depends upon the subclassification of acute lymphatic leukemia and the age of the patient (pediatric or adult)
Suspension: For acute lymphoblastic leukemia as part of a combination regimen

Usual Pediatric Dose for Intestinal Arterial Insufficiency

TABLETS:

MAINTENANCE THERAPY: When a complete hematologic remission is obtained, maintenance therapy is considered essential. Maintenance doses vary. The usual daily maintenance dose is 1.5 to 2.5 mg/kg/day orally as a single dose. This drug should rarely be relied upon as a single agent for the maintenance of remissions induced in acute leukemia.
DOSAGE WITH CONCOMITANT ALLOPURINOL: When this drug is given concomitantly with allopurinol, the dose of this drug should be reduced to one-third to one-quarter of the usual dose to avoid severe toxicity.

SUSPENSION:

MAINTENANCE THERAPY: The recommended starting dose of this drug in multi-agent combination chemotherapy maintenance regimens is 1.5 to 2.5 mg/kg (50 to 75 mg/m2) orally as a single daily dose.
HOMOZYGOUS DEFICIENCY IN EITHER TPMT OR NUDT15: Patients with homozygous deficiency of either enzyme typically require 10% or less of the standard oral suspension dose. Reduce initial dose in patients who are known to have homozygous TPMT or NUDT15 deficiency.
HETEROZYGOUS DEFICIENCY IN TPMT AND/OR NUDT15: Reduce the oral suspension dose based on tolerability. Most patients with heterozygous TPMT or NUDT15 deficiency tolerate recommended doses, but some require dose reduction based on toxicities. Patients who are heterozygous for both TPMT and NUDT15 may require more substantial dosage reductions.

Comments:

The dosage recommendations presented here are manufacturer suggested; consult local institutional guidelines for alternate dosing options.
After initiating therapy, monitor complete blood counts (CBCs), transaminases, and bilirubin.
Maintain ANC at a desirable level by reducing the dose in patients with excessive hematological toxicity.
Evaluate the bone marrow in patients with prolonged or repeated marrow suppression to assess leukemia status and marrow cellularity.
Evaluate thiopurine S-methyltransferase (TPMT) and nucleotide diphosphatase (NUDT15) status in patients with clinical or laboratory evidence of severe bone marrow toxicity, or repeated episodes of myelosuppression.
There is no general agreement that the procedures recommended in the guidelines are necessary or appropriate.

Use:

Tablets: For maintenance therapy of acute lymphatic (lymphocytic, lymphoblastic) leukemia as part of a combination regimen; response to this agent depends upon the subclassification of acute lymphatic leukemia and the age of the patient (pediatric or adult)
Suspension: For acute lymphoblastic leukemia as part of a combination regimen

Usual Pediatric Dose for Acute Lymphoblastic Leukemia

TABLETS:

MAINTENANCE THERAPY: When a complete hematologic remission is obtained, maintenance therapy is considered essential. Maintenance doses vary. The usual daily maintenance dose is 1.5 to 2.5 mg/kg/day orally as a single dose. This drug should rarely be relied upon as a single agent for the maintenance of remissions induced in acute leukemia.
DOSAGE WITH CONCOMITANT ALLOPURINOL: When this drug is given concomitantly with allopurinol, the dose of this drug should be reduced to one-third to one-quarter of the usual dose to avoid severe toxicity.

SUSPENSION:

MAINTENANCE THERAPY: The recommended starting dose of this drug in multi-agent combination chemotherapy maintenance regimens is 1.5 to 2.5 mg/kg (50 to 75 mg/m2) orally as a single daily dose.
HOMOZYGOUS DEFICIENCY IN EITHER TPMT OR NUDT15: Patients with homozygous deficiency of either enzyme typically require 10% or less of the standard oral suspension dose. Reduce initial dose in patients who are known to have homozygous TPMT or NUDT15 deficiency.
HETEROZYGOUS DEFICIENCY IN TPMT AND/OR NUDT15: Reduce the oral suspension dose based on tolerability. Most patients with heterozygous TPMT or NUDT15 deficiency tolerate recommended doses, but some require dose reduction based on toxicities. Patients who are heterozygous for both TPMT and NUDT15 may require more substantial dosage reductions.

Comments:

The dosage recommendations presented here are manufacturer suggested; consult local institutional guidelines for alternate dosing options.
After initiating therapy, monitor complete blood counts (CBCs), transaminases, and bilirubin.
Maintain ANC at a desirable level by reducing the dose in patients with excessive hematological toxicity.
Evaluate the bone marrow in patients with prolonged or repeated marrow suppression to assess leukemia status and marrow cellularity.
Evaluate thiopurine S-methyltransferase (TPMT) and nucleotide diphosphatase (NUDT15) status in patients with clinical or laboratory evidence of severe bone marrow toxicity, or repeated episodes of myelosuppression.
There is no general agreement that the procedures recommended in the guidelines are necessary or appropriate.

Use:

Tablets: For maintenance therapy of acute lymphatic (lymphocytic, lymphoblastic) leukemia as part of a combination regimen; response to this agent depends upon the subclassification of acute lymphatic leukemia and the age of the patient (pediatric or adult)
Suspension: For acute lymphoblastic leukemia as part of a combination regimen

Renal Dose Adjustments

Starting at the low end of the dosing range, or increasing the dosing interval to 36 to 48 hours should be considered in patients with baseline renal impairment.

Liver Dose Adjustments

Consideration should be given to reducing the dosage in patients with impaired hepatic function.

Precautions

CONTRAINDICATIONS:

Hypersensitivity to the active component or any of the ingredients
This drug should not be used in patients whose disease has demonstrated prior resistance to it

Consult WARNINGS section for additional precautions.

Dialysis

Data not available

Other Comments

Administration advice:

This is a potent drug. It should not be used unless the physician is experienced with the risks and knowledgeable in assessing response to chemotherapy.

Patient advice:

Patients should be informed that the major toxicities of this drug are related to myelosuppression, hepatotoxicity, and GI toxicity.
Patients should not be allowed to take the drug without medical supervision and should be advised to consult their physician if they experience fever, sore throat, jaundice, nausea, vomiting, signs of local infection, bleeding from any site, or symptoms of anemia.
Women of childbearing potential should be advised to avoid becoming pregnant.