6-mercaptopurine

Definition

6-mercaptopurine is a purine analog and an antimetabolite used primarily in the treatment of certain autoimmune disorders and cancers, particularly leukemia. By inhibiting the synthesis of purines, it disrupts the proliferation of rapidly dividing cells, making it effective for conditions characterized by abnormal immune responses.

5 Must Know Facts For Your Next Test

1. 6-mercaptopurine is commonly used to treat acute lymphoblastic leukemia (ALL) and Crohn's disease.
2. Patients taking 6-mercaptopurine may require monitoring for liver function and potential hematological side effects, such as myelosuppression.
3. The drug is metabolized by the enzyme thiopurine methyltransferase (TPMT), and genetic testing for TPMT activity can help tailor doses to individual patients.
4. 6-mercaptopurine can interact with other medications, especially those affecting the liver enzymes involved in its metabolism, leading to increased toxicity.
5. It's important for patients to avoid certain foods and medications that may affect the drug's efficacy and increase the risk of side effects.

Review Questions

• How does 6-mercaptopurine act as an antimetabolite in the treatment of autoimmune disorders?
  • 6-mercaptopurine acts as an antimetabolite by mimicking purines, which are necessary for DNA and RNA synthesis. By disrupting the normal synthesis of these nucleotides, it inhibits cell proliferation. This mechanism is particularly beneficial in treating autoimmune disorders, where the immune system is overactive, allowing for a reduction in pathological immune responses.
• Discuss the significance of monitoring liver function and hematological parameters in patients receiving 6-mercaptopurine therapy.
  • Monitoring liver function and hematological parameters is critical for patients on 6-mercaptopurine due to the risk of liver toxicity and myelosuppression. Liver function tests help detect any potential damage early on, while regular blood counts can identify drops in white blood cell or platelet counts, which can lead to increased infection risk or bleeding. This proactive approach helps ensure patient safety and effective management of therapy.
• Evaluate how genetic testing for TPMT activity can influence treatment plans involving 6-mercaptopurine.
  • Genetic testing for TPMT activity allows healthcare providers to personalize treatment plans for patients prescribed 6-mercaptopurine. Patients with low or absent TPMT activity are at increased risk for severe toxicity due to higher levels of the drug in their system. By identifying these individuals, clinicians can adjust dosages accordingly or consider alternative therapies, ultimately improving treatment outcomes and minimizing adverse effects.

Related terms

Antimetabolite: A class of drugs that interfere with DNA and RNA synthesis, commonly used in cancer therapy and autoimmune diseases.

Purine: A type of nitrogenous base that is a component of nucleotides; essential for DNA and RNA synthesis.

Immunosuppressant: A drug that reduces the strength of the body's immune system, often used in autoimmune disorders and organ transplantation.