🍽️ mercaptopurine,(prescription)

Antineoplastic Activity: Mercaptopurine is classified as an antimetabolite and immunosuppressive agent. It works by interfering with the synthesis of DNA and RNA in rapidly dividing cells, including cancer cells, thereby inhibiting their proliferation and inducing cell death. In the treatment of ALL, mercaptopurine is often used as part of combination chemotherapy regimens to achieve remission and prevent disease recurrence.

Induction and Maintenance Therapy for ALL: Mercaptopurine is a key component of multi-agent chemotherapy protocols used in the induction and maintenance phases of treatment for ALL, particularly in pediatric patients. It helps eradicate leukemic cells from the bone marrow and peripheral blood, leading to remission and improving overall survival rates. Mercaptopurine may be used in combination with other chemotherapeutic agents such as methotrexate, vincristine, and corticosteroids.

Immunosuppressive Effects: In addition to its anticancer properties, mercaptopurine exhibits immunosuppressive effects by inhibiting the proliferation of T and B lymphocytes and suppressing immune responses. This mechanism of action is utilized in the treatment of autoimmune disorders such as Crohn's disease and ulcerative colitis, where excessive immune activation contributes to inflammation and tissue damage in the gastrointestinal tract.

Maintenance of Remission in Inflammatory Bowel Disease (IBD): Mercaptopurine is effective in maintaining remission and preventing disease flare-ups in patients with Crohn's disease and ulcerative colitis who have achieved clinical remission with initial therapy. By modulating immune function and reducing inflammation, mercaptopurine helps control symptoms, promote mucosal healing, and prolong periods of disease quiescence.

Thiopurine Metabolism and Genetic Variability: Mercaptopurine is a prodrug that undergoes extensive metabolism in the body, primarily via the thiopurine S-methyltransferase (TPMT) pathway. Genetic variations in the TPMT gene can influence individual responses to mercaptopurine therapy, with deficient or absent TPMT activity associated with an increased risk of severe myelosuppression and other adverse effects. TPMT genotyping or phenotyping may be performed to guide dosing and reduce the risk of toxicity.

Side Effects and Adverse Reactions: Common side effects of mercaptopurine therapy include bone marrow suppression (resulting in leukopenia, thrombocytopenia, and anemia), gastrointestinal disturbances (such as nausea, vomiting, and diarrhea), hepatotoxicity, pancreatitis, and increased susceptibility to infections. Patients receiving mercaptopurine require close monitoring of blood cell counts, liver function tests, and clinical symptoms to detect and manage potential complications.

Drug Interactions: Mercaptopurine may interact with other medications, including allopurinol (which inhibits mercaptopurine metabolism), azathioprine (which has similar immunosuppressive properties), and drugs that affect hepatic metabolism or renal excretion. Concomitant use of mercaptopurine with other potentially myelosuppressive agents or hepatotoxic drugs should be carefully monitored to avoid additive adverse effects.

Pregnancy and Fertility: Mercaptopurine is classified as a pregnancy category D medication due to its teratogenic effects and potential harm to the fetus. Women of childbearing age receiving mercaptopurine therapy should use effective contraception to prevent pregnancy during treatment. Additionally, mercaptopurine may impair fertility in both men and women, and counseling regarding reproductive risks and options should be provided to patients prior to initiating therapy.