Oncology Flashcards
Methotrexate (MTX)
Antimetabolite
Folic acid analog that inhibits dihydrofolate reductase, decreases dTMP, and decreases DNA and protein synthesis.
Leukemias, lymphomas, choriocarcinoma, sarcomas; abortion, ectopic pregnancy, rheumatoid arthritis, psoriasis, IBD
Myelosuppression (reversible with leucovorin/folinic acid rescue), macrovesicular fatty change in liver, mucositis, teratogenic.
5-fluorouracil (5-FU)
Antimetabolite
Pyrimidine analog bioactivated to 5F-dUMP, which covalently complexes folic acid. Inhibits thymidylate synthase, decreases dTMP, and decreases DNA and protein synthesis.
Colon cancer, pancreatic cancer, basal cell carcinoma (topical)
Myelosuppression, which is not reversible with leucovorin. “Rescue” overdose with uridine. Photosensitivity.
Cytarabine (arabinofuranosyl cytidine)
Antimetabolite
Pyrimidine analog, inhibits DNA polymerase
Leukemias, lymphomas
Leukopenia, thrombocytopenia, megaloblastic anemia (panCYTopenia)
Azathioprine
Antimetabolite
Purine (thiol) analog, decreases de novo purine synthesis. Activated by HGPRT
Prevention of organ rejection, RA, SLE
Bone marrow, GI, liver toxicity. Increased toxicity with allopurinol (inhibits metabolism)
6-mercaptopurine (6-MP)
Antimetabolite
Purine (thiol) analog, decreases de novo purine synthesis. Activated by HGPRT
Prevention of organ rejection, RA, leukemia, IBD
Bone marrow, GI, liver toxicity. Increased toxicity with allopurinol (inhibits metabolism)
6-thioguanine (6-TG)
Antimetabolite
Purine (thiol) analog, decreases de novo purine synthesis. Activated by HGPRT
Prevention of organ rejection, RA, leukemia, IBD
Bone marrow, GI, liver toxicity.
Dactinomycin (Actinomycin D)
Antitumor antibiotic
Intercalates in DNA
Wilms tumor, Ewing sarcoma, rhabdomyosarcoma. Used for childhood tumors.
Myelosuppression
Doxorubicin (Adriamycin)
Antitumor antibiotic
Generate free radicals. Intercalates in DNA, leading to breaks in DNA and decreased replication.
Solid tumors, leukemias, lymphomas
Cardiotoxicity (dilated cardiomyopathy), myelosuppression, alopecia. Toxic to tissues following extravasation.
Use dexrazoxane (iron chelating agent) to prevent cardiotoxicity.
Daunorubicin
Antitumor antibiotic
Generate free radicals. Intercalates in DNA, leading to breaks in DNA and decreased replication.
Solid tumors, leukemias, lymphomas
Cardiotoxicity (dilated cardiomyopathy), myelosuppression, alopecia. Toxic to tissues following extravasation.
Use dexrazoxane (iron chelating agent) to prevent cardiotoxicity.
Bleomycin
Antitumor antibiotic
Induces free radical generation, which causes breaks in DNA strands
Testicular cancer, Hodgkin lymphoma
Pulmonary fibrosis, skin changes, mucositis. Minimal myelosuppression.
Cyclophosphamide
Alkylating agent
Covalently cross-link (interstrand) DNA at guanine N-7. Requires bioactivation by liver.
Solid tumors, leukemia, lymphomas, some brain cancers.
Myelosuppression, hemorrhagic cystitis, partially prevented with mesna (thiol group of mesna binds toxic metabolites)
Ifosfamide
Alkylating agent
Covalently cross-link (interstrand) DNA at guanine N-7. Requires bioactivation by liver.
Solid tumors, leukemia, lymphomas, some brain cancers.
Myelosuppression, hemorrhagic cystitis, partially prevented with mesna (thiol group of mesna binds toxic metabolites)
Carmustine
Alkylating agent (nitrosurea) Cross-links DNA. Require bioactivation by liver. Cross BBB to enter CNS. Brain tumors (including glioblastoma multiforme) CNS toxicity (convulsions, ataxia, dizziness)
Lomustine
Alkylating agent (nitrosurea) Cross-links DNA. Require bioactivation by liver. Cross BBB to enter CNS. Brain tumors (including glioblastoma multiforme) CNS toxicity (convulsions, ataxia, dizziness)
Semustine
Alkylating agent (nitrosurea) Cross-links DNA. Require bioactivation by liver. Cross BBB to enter CNS. Brain tumors (including glioblastoma multiforme) CNS toxicity (convulsions, ataxia, dizziness)
