Cancer Cytotoxic Agents Pharmacology Flashcards
Antimetabolites exampls
Folic acid analogues
Purine analogs
Pyrimidine analogs
Antimetabolites MOA
Act at S phase as structural analogs and antagonists of endogenous biochemiclas that inhibit purine and pyrimidine
Methotrexate MOA
Inhibit dihydrofolate reducttion, blocks thymidine & purine synthesis (S-phase)
5-fluorouracil MOA
Inhibits thymidylate synthesis (S-phase)
Leucovorin Rescue
Used to replenish folate pools in normal cells. The window is tight and must be used within a 48 hour window
6MP and 6TG specific MOA
Activation by HGPRT to form triphosphate metabolite. Inhibits biosynthesis of endogenous purines
Fludarabine monophosphate (Fludara) MOA
Phosphorylation causes activation and then inhibits DNA polymerase causing DNA chain termination
Cladribine (Leustatin) MOA
Phosphorylation causes activation and inhibits DNA synthesis and repair
5-fluorouracil MOA
FdUMP is formed from 5-FU. FdUMP inhibits thymidylate synthase activity causing thymine starvation and DNA synthesis
Capecitabine (Xeloda) MOA
Prodrug that requires many enzymes to being active form 5FU. Leads to cytotoxicity similar to 5FU
TAS-102 (Lonsurf)
Trifluridine and tipiracil
MOA
Trfluridine is inactive parent form. Tipiracil is an enzyme that degrades trifluridine which will then inhibit thymidylate synthase
Cytarabine (ara-C) MOA
Ara-C bioactivated to araCMP which inhibits DNA polymerase alpha and beta blocking DNA synthesis and repair.
Gemcitabine MOA
Structure and MOA similar to ara-C. (DNA polymerase alpha and beta blocking synthesis and repair)
Methotrexate dose limiting toxicities
myelosuppression (immune suppression) and mucositis (oral and intestinal ulcerations)
6-MP dose limiting toxicities
myelosuppression, mucositis, GI distress, and hepatotoxicity