Onc drugs Flashcards
What class of drug is azathioprine, 6-MP/6-TG?
Anti-metabolite
What is the mechanism of action of azathioprine, 6-MP/6-TG?
- Purine (thiol) analogs decrease de novo purine synthesis.
- Activated by HGPRT
- Azathioprine is metabolized to 6MP.
What is the clinical use for azathioprine, 6-MP/6-TG?
Preventing organ rejection, rheumatoid arthritis, IBD, SLE; used to wean patients off steroids in chronic disease and to treat steroid-refractory chronic disease.
What is the toxicity of azathioprine, 6-MP/6-TG?
Myelosuppression, GI, liver.
What drugs do azathioprine etc have increased risk of toxicity with and why?
allopurinol or febuxostat, because metabolized by xanthine oxidase.
What class of drug is cladribine (2-CDA)?
Antimetabolite
What is the mechanism of action of cladribine?
Purine analog, multiple
mechanisms (e.g., inhibition
of DNA polymerase, DNA
strand breaks).
What is the clinical use of cladribine?
Hairy cell leukemia.
What are the toxicities of cladribine?
Myelosuppression,
nephrotoxicity, and
neurotoxicity.
What drug class is cytarabine (arabinofurosyl cytidine)?
Pyrimidine analog –> inhibition of DNA polymerase.
What is the clinical use for cytarabine (arabinofurosyl cytidine?
Leukemias (AML), lymphomas
What are the toxicities of cytarabine (arabinofurosyl cytidine?
Leukopenia, thrombocytopenia, megaloblastic anemia. (CYTarabine causes panCYTopenia.)
What drug class is 5-FU?
antimetabolite
What is the mechanism of action of 5-FU?
Pyrimidine analog bioactivated to 5F-dUMP, which covalently complexes folic acid. This complex inhibits thymidylate synthase , resulting in decr dTMP and decr DNA synthesis.
What is the clinical use of 5-FU?
Colon cancer, pancreatic
cancer, basal cell carcinoma
(topical).
What are the toxicities of 5-FU?
Myelosuppression, which is
not reversible with leucovorin
(folinic acid).
What drug class is methotrexate?
Antimetabolite
What is the mechanism of action of methotrexate?
Folic acid analog that
competitively inhibits
dihydrofolate reductase, decreasedTMP and decreaseDNA
synthesis.
What drug class is bleomycin?
Anti-tumor antibiotic
What is the mechanism of action of bleomycin?
Induces free radical formation –> breaks in DNA strands.
What is the clinical use of bleomycin?
Testicular cancer, Hodgkin’s lymphoma.
What is the toxicity associated with bleomycin?
Pulmonary fibrosis, skin hyperpigmentation,
mucositis. Minimal myelosuppression
What drug class is dactinomycin/actinomycin D?
Anti-tumor antibiotic.
What is the mechanism of action of dactinomycin/actinomycin D?
Intercalates in DNA - binds DNA at the transcription site and won’t let go.
What is the clinical use of dactinomycin/actinomycin D?
Childhood tumors - wilms tumor, ewiing sarcoma, rhabdomyosarcoma.
What is the toxicity associated with dactinomycin/actinomycin D?
Myelosuppresion.
What drug class is doxorubiin/daunorubicin?
Generates free radials, intercalates in DNA, breaks in DNA, decr replication
What is the clinical use of doxorubicin/daunorubicin?
Solid tumors, leukemias, lymphomas
What is the toxicity assoicated with doxorubicin/daunorubicin?
Cardiotoxicity (dilated cardiomyopathy), myelosuppression, alopecia. Toxic to tissues following extravasation.
What is used to prevent cardiotoxicity of doxorubicin?
Dexrazone (iron chelating agent).
What drug class is busulfan?
Alkylating agent
What is the mechanism of busulfan?
Cross-links DNA
What is the clinical use of busulfan?
CML. Also used to ablate patient’s bone marrows before transplantation.
What is the toxicity of busulfan?
Severe myelosuppression (in almost all cases), pulmonary fibrosis, hyperpigmentation.
What drug class is cyclophosphamide/ifosphamide?
Alkylating agents
What is the mechanism of cyclophosphamide/ifosphamide?
Cross-link DNA at guanine
N-7. Require bioactivation by
liver.
What is the clinical use of cyclophosphamide/ifosphamide?
Solid tumors, leukemia, lymphoma
What is the toxicity of cyclophosphamide/ifosphamide?
Myelosuppression; hemorrhagic cystitis, partially prevented with mesna (thiol group of mesna binds toxic metabolites).
What is the drug class of the nitrosoureas?
Alkylating agents
What are carmustine, lomustine, semustine, and streptozicin?
nitrosoureas
What is the mechanism of action of nitrosoureas?
Require bioactivation.
Cross blood-brain barrier
CNS. Cross-link DNA.
What is the clinical use of nitrosoureas?
Brain tumors incl GBM.
What are the toxicities of nitrosoureas?
CNS toxicity - convulsions, dizziness, ataxia.
What drug class is paclitaxel/other taxols?
Microtubule inhibitors
What is the mechanism of action of paclitaxel?
Hyperstabilize polymerized microtubules in M phase so that mitotic spindle cannot break down (anaphase cannot occur).
What is the clinical use of paclitaxel?
Ovarian and breast carcinoma.
What are the toxicities of paclitaxel?
Myelosuppression, alopecia,
hypersensitivity.
What drug class is vincristine/vinblastine?
Vinca alkyloids/microtubule inhibitors.
What is the mechanism of action of vincristine/vinblastine?
Vinca alkaloids that bind β-tubulin and inhibit its polymerization into microtubules prevent mitotic spindle formation (M-phase arrest).
What is the clinical use of vincristine/vinblastine?
Solid tumors, leukemias, Hodgkin (vinblastine) and non-Hodgkin (vincristine) lymphomas. (blast the owl).
What are the toxicities of vincristine/vinblastine?
Vincristine: neurotoxicity (areflexia, peripheral neuritis), paralytic ileus. Vinblastine blasts bone marrow (suppression).
What is the mechanism of cisplatin/carboplatin?
Cross-link DNA.
What is the clinical use of cisplatin/carboplatin?
Testicular, bladder, ovary, and lung carcinomas.
What are the toxicities of cisplatin/carboplatin?
Nephrotoxicity, ototoxicity.
What can be used to prevent cisplatin/carboplatin nephrotoxicity?
Prevent nephrotoxicity with amifostine (free radical scavenger) and
chloride (saline) diuresis.
What is the mechanism of etoposide/teniposide?
Etoposide inhibits topoisomerase II; Incr DNA degradation.
What is the clinical use of etoposide/teniposide?
Solid tumors (particularly testicular and small cell lung cancer), leukemias, lymphomas.
What are the toxicities of etoposide/teniposide?
Myelosuppression, GI upset, alopecia.
What is the mechanism of irinotecan/topotecan?
Inhibit topoisomerase I and prevent DNA unwinding and replication.
What is the clinical use of irinotecan/topotecan?
Colon cancer (irinotecan); ovarian and small cell lung cancers (topotecan).
What are the toxicities of irinotecan/topotecan?
Severe myelosuppression, diarrhea.
What is the mechanism of hydroxyurea?
Inhibits ribonucleotide reductase ; Decrease DNA Synthesis (S-phase specific).
What is the clinical use of hydroxyurea?
Melanoma, CML, sickle cell disease ( HbF).
What are the toxicities of hydroxyurea?
Severe myelosuppression, GI upset.
What is the mechanism of action of prednisone/prednisolone?
Various; bind intracytoplasmic receptor; alter gene transcription.
What are the clinical uses of prednisone/prednisolone?
Most commonly used glucocorticoids in cancer chemotherapy. Used in CLL, non-Hodgkin
lymphoma (part of combination chemotherapy regimen). Also used as immunosuppressants (e.g.,
in autoimmune diseases).
What are the toxicities of prednisone/prednisolone?
Cushing-like symptoms; weight gain, central obesity, muscle breakdown, cataracts, acne,
osteoporosis, hypertension, peptic ulcers, hyperglycemia, psychosis.
What is the mechanism of bevacizumab?
Monoclonal antibody against VEGF. Inhibits angiogenesis.
What are the clinical uses of bevacizumab?
Solid tumors (colorectal cancer, renal cell carcinoma).
What are the toxicities of bevacizumab?
Hemorrhage, blood clots, and impaired wound healing.
What is the mechanism of erlotinib?
EGFR tyrosine kinase inhibitor.
What are the clinical uses of erlotinib?
Non-small cell lung carcinoma.
What are the toxicities of erlotinib?
Rash.
What is the mechanism of imatinib?
Tyrosine kinase inhibitor of BCR-ABL (Philadelphia chromosome fusion gene in CML) and c-kit
(common in GI stromal tumors).
What are the clinical uses of imatinib?
CML, GI stromal tumors.
What are the toxicities of imatinib?
Fluid retention.
What is the mechanism of rituximab?
Monoclonal antibody against CD20, which is found on most B-cell neoplasms
What are the clinical uses of rituximab?
Non-Hodgkin lymphoma, CLL, IBD, rheumatoid arthritis.
What are the toxicities of rituximab?
Incr risk of progressive multifocal leukoencephalopathy.
What is the mechanism of tamoxifen/raloxifene?
Selective estrogen receptor modulators (SERMs)—receptor antagonists in breast and agonists in
bone. Block the binding of estrogen to ER
⊕ cells.
What are the clinical uses of tamoxifen/raloxifene?
Breast cancer treatment (tamox only) and prevention. Raloxifene also useful to prevent osteoporosis.
What are the toxicities of tamoxifen/raloxifene?
Tamoxifen—partial agonist in endometrium, which the risk of endometrial cancer; “hot flashes.”
Raloxifene—no in endometrial carcinoma because it is an estrogen receptor ANTAGONIST in
endometrial tissue.
What is the mechanism of trastuzumab?
Monoclonal antibody against HER-2 (c-erbB2), a tyrosine kinase receptor.
Helps kill cancer cells
that overexpress HER-2, through inhibition of HER2-initiated cellular signaling and antibody-dependent cytotoxicity.
What are the clinical uses of trastuzumab?
HER-2⊕ breast cancer and gastric cancer (tras2zumab).
What are the toxicities of trastuzumab?
Cardiotoxicity. “Heartceptin” damages the heart.
What is the mechanism of vemurafenib?
Small molecule inhibitor of BRAF oncogene
⊕ melanoma
What is the clinical use of vemurafenib?
Metastatic melanoma