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PURIXAN is indicated for the treatment of patients with acute lymphoblastic leukemia (ALL) as a component of a combination maintenance therapy regimen.

Liquid Formulation

PURIXAN offers patients and healthcare professionals a liquid formulation as an alternative to the mercaptopurine tablet for precise dosing based on the individual patient’s dosing needs.

  • Mercaptopurine is a cornerstone of all maintenance therapy drug regimens for acute lymphoblastic leukemia (ALL).1
  • Until recently, the only marketed formulation of mercaptopurine has been a 50-mg tablet.
    • However, solid oral dosage forms may be ineffective for many children because they have difficulty swallowing tablets and capsules.2
    • Fixed doses are impractical because the dose varies according to the size of the child.2
    • More than 90% of pediatricians reported that a drug’s taste and palatability were the greatest barriers to compliant treatment.2
  • For children, PURIXAN addresses common concerns relating to treatment with a tablet.

Comparison between PURIXAN and the tablet form of mercaptopurine

The bioavailability of PURIXAN is equivalent to that of the tablet form of mercaptopurine, as measured by the AUC (area under the concentration curve).

  • The mean ratio of the AUCs for PURIXAN and mercaptopurine tablets is 114%, with a 90% confidence interval of 108%–121%. 3
  • The accepted target range of AUC ratios for equivalence is 80%–125%.3


PURIXAN performs more consistently and predictably than the mercaptopurine tablet.

  • PURIXAN had substantially lower between-subject variability in maximum plasma concentrations (46% vs 69% coefficient of variation).3

Consistent Absorption

PURIXAN reduced the variability in the absorption of mercaptopurine, proving itself to be a dependable and reliable alternative to the tablet.3



Flexibility and Accuracy

PURIXAN provides dosing flexibility and accuracy for precise dosing.

PURIXAN 20 mg/mL oral suspension provides an accuracy of 2 mg and an opportunity to administer the product in a way that may be more acceptable to children.2


  1. Pui CH, Evans WE. Treatment of acute lymphoblastic leukemia. N Engl J Med. 2006;354:166-178.
  2. Mennella JA, Spector AC, Reed DR, Coldwell SE. The bad taste of medicines: overview of basic research on bitter taste. Clin There. 2013;35:1225-1246.
  3. Mulla H, Leary A, White P, Pandya H. A step toward more accurate dosing for mercaptopurine in childhood acute lymphoblastic leukemia. J Clin Pharmacol. 2012;52:1610-1613.
  4. WHO growth chart for children. Accessed April 16, 2020.
  5. PURIXAN (mercaptopurine) oral suspension [package insert]. Franklin, TN: Rare Disease Therapeutics, Inc.; April 2020.


Package Insert

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How to use Purixan®


Return Policy

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PURIXAN® (mercaptopurine) is a nucleoside metabolic inhibitor indicated for the treatment of patients with acute lymphoblastic leukemia (ALL) as a component of a combination maintenance therapy regimen.

Warnings and Precautions

Monitor complete blood count (CBC) and adjust the dose of PURIXAN 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-TPMT or homozygous-NUDT15 deficiency may require a dose reduction.

Monitor transaminases, alkaline phosphatase and bilirubin. Withhold PURIXAN at onset of hepatotoxicity.

Response to all vaccines may be diminished and there is a risk of infection with live virus vaccines. Consult immunization guidelines for immunocompromised pediatrics.

Treatment Related Malignancies
Aggressive and fatal cases of hepatosplenic T-cell lymphoma have occurred.

Macrophage Activation Syndrome
Monitor for and treat promptly; discontinue PURIXAN.

Embryo-Fetal Toxicity
Can cause fetal harm. Advise patients of reproductive potential of the potential risk to a fetus and to use effective contraception.


Adverse Reactions

Adverse Reactions – Clinical Studies Experience
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.

Adverse Reactions – Postmarketing Experience
The following adverse reactions have been identified during postapproval use of PURIXAN. 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, and portal hypertension.

See Full Prescribing Information

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