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Understanding Antimetabolites in Medicine

Mar 29, 2025

Lecture Notes: Antimetabolite Agents

Case Study: GM's Rheumatoid Arthritis

  • Patient Profile: GM, 47-year-old woman
  • Condition: Newly diagnosed with rheumatoid arthritis, experiencing hand pain
  • Initial Treatment Recommendations:
    • Methotrexate: Suggested as a disease-modifying antirheumatic drug (DMARD)
    • Naproxen: Recommended for pain control until stabilized
  • Patient Concerns:
    • Methotrexate is questioned due to its immunosuppressant properties
    • Patient is a nurse and hesitant about immunosuppressive therapy

Cancer Cell DNA Replication

  • Cancer cells replicate DNA unregulated, incorporating nucleosides into DNA chains.
  • Vulnerability: Cancer cells incorporate compounds resembling nucleosides.

Role of Antimetabolites in Chemotherapy

  • Function: Exploit cancer cell vulnerability by acting as nucleoside analogs
  • Mechanism:
    • Analog Structure: Mimic substrates in pyrimidine and purine synthesis
    • Action: Serve as decoys which interrupt DNA synthesis
    • Outcome: Causes cell death by disrupting normal DNA synthesis

Key Points

  • Antimetabolites are crucial in chemotherapy for targeting rapidly replicating cancer cells.
  • Methotrexate, an example of an antimetabolite, can also be used in autoimmune conditions like rheumatoid arthritis, although it raises concerns about immunosuppression.

Considerations

  • Weigh the benefits of methotrexate in managing rheumatoid arthritis against potential risks of immunosuppression, especially in healthcare workers like GM.