Methotrexate (MTX)

•  Mechanism of Action: Folic acid antagonist: acts at catalytic side of dihydrofolate reductase
  • Polyglutamate: important in methotrexate action
  • Tumor resistance to methotrexate: several mechanisms
•  Adverse effects:
  • Bone marrow suppression
  • Dermatologic
  • GI mucosa
  • Adverse effects reversed by leucovorin (citrovorum factor)
    • Leucovorin "rescue" may be used in cases of over dosage or in high-those methotrexate protocols
• Other uses:
  • Treatment of rheumatoid arthritis
  • In combination with a prostaglandin: induces abortion