Mercaptopurine, also known as 6-mercaptopurine or 6-MP, is a potent antimetabolite used primarily in the treatment of certain types of cancer, including acute lymphoblastic leukemia (ALL). It functions by interfering with the synthesis of purine nucleotides, which are essential components of DNA and RNA, thereby inhibiting the proliferation of rapidly dividing cancer cells. This mechanism of action makes mercaptopurine a critical component in chemotherapy regimens, particularly in maintenance therapy for ALL.

In addition to its oncological applications, mercaptopurine is also utilized in the management of autoimmune conditions such as Crohn's disease and ulcerative colitis. By modulating the immune response, it helps reduce inflammation and maintain remission in these chronic conditions. The pharmacokinetics of mercaptopurine involve hepatic metabolism, primarily through the enzyme thiopurine S-methyltransferase (TPMT), which can vary significantly among individuals, affecting both efficacy and toxicity.

Due to its narrow therapeutic index, careful monitoring of blood counts and liver function is essential during treatment with mercaptopurine. Genetic testing for TPMT activity may be recommended to tailor dosing and minimize adverse effects. Common side effects include myelosuppression, hepatotoxicity, and gastrointestinal disturbances, necessitating a personalized approach to therapy. As a compounding pharmacy, Bayview Pharmacy is committed to providing customized formulations of mercaptopurine to meet the specific needs of patients, ensuring optimal therapeutic outcomes.