Prevall Oral Suspension

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. Acute Lymphoblastic Leukemia Mercaptopurine is indicated for the treatment of patients with acute lymphoblastic leukemia (ALL) as part of a combination chemotherapy maintenance regimen.

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Source: US FDA prescribing information, via openFDA. Provided for general information only — it is not a substitute for your doctor's or pharmacist's advice. Always follow your prescriber's instructions.

• Myelosuppression: Monitor complete blood count (CBC) and adjust the dose of Mercaptopurine 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. - Hepatotoxicity: Monitor transaminases, alkaline phosphatase and bilirubin. Withhold Mercaptopurine at onset of hepatotoxicity. - Immunosuppression: 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 Mercaptopurine. - Embryo-Fetal Toxicity: Can cause fetal harm. Advise patients of reproductive potential of the potential risk to a fetus and to use effective contraception. - Phenylketonuria: Patients should be informed that Mercaptopurine oral suspension contains phenylalanine, a component of aspartame. Each mL of the 20 mg/mL oral suspension contains 0.015 mg of phenylalanine. Myelosuppression The most consistent, dose-related adverse reaction of Mercaptopurine is myelosuppression, manifested by anemia, leukopenia, thrombocytopenia, or any combination of these. Monitor CBC and adjust the dosage of Mercaptopurine for excessive myelosuppression. Consider testing for thiopurine S-methyltransferase (TPMT) or nucleotide diphosphatase (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 homozygous TPMT or NUDT15 deficiency may require a dose reduction. Myelosuppression can be exacerbated by coadministration with allopurinol, aminosalicylates or other products that cause myelosuppression. Reduce the dosage of Mercaptopurine when coadministered with allopurinol. Hepatotoxicity 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); Abridged from the full prescribing information.

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Source: US FDA prescribing information, via openFDA. Provided for general information only — it is not a substitute for your doctor's or pharmacist's advice. Always follow your prescriber's instructions.

The following clinically significant adverse reactions are described elsewhere in the labeling: - Myelosuppression - Hepatotoxicity - Immunosuppression - Treatment Related Malignancies - Macrophage Activation Syndrome 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. 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. Drug fever has been reported with Mercaptopurine. 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.

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Source: US FDA prescribing information, via openFDA. Provided for general information only — it is not a substitute for your doctor's or pharmacist's advice. Always follow your prescriber's instructions.