Pharmacology Flashcards
what antineoplastics act on the mitosis stage of cell cycle? what exactly do they do?
- vinca alkaloids inhibit microtubule formation
- paclitaxel (trade name Taxol) inhibits microtubule disassembly
what antineoplastics prevent nucleotide synthesis?
methotrexate and 5-FU inhibit thymidine synthesis
6-mercaptopurine (6-MP) inhibits purine synthesis
what antineoplastics ruin existing DNA?
- alkylating agents and cisplatin cross-link DNA
- doxorubicin and dactinomycin intercalate DNA
- etoposide inhibits topoisomerase II (which normally relieves supercoils in the DNA)
what exactly is methotrexate (molecule-wise) and what is it used to treat (cancer and non-cancer uses)?
folic acid analogue that inhibits DHF reductase; cancer uses: leukemia, lymphoma, choriocarcinoma
non-cancer uses: abortion, ectopic pregnancy, rheumatoid arthritis, psoriasis
what toxicities does methotrexate use cause?
myelosuppresion (reversed by lucovorin aka folinic acid rescue); macrovesicular fatty change in the liver; mucositis; teratogen
what exactly is 5-FU and what does it inhibit?
5F-dUMP (deoxyuridine monophosphate) analog that inhibits thymidylate synthase which normally converts dUMP to dTMP
what is 5-FU used to treat?
colon cancer, basal cell carcinoma (topical Tx)
what toxicities are associated with 5-FU
myelosuppression (not rescueable with leucovorin, must use thymidine);
photosensitivity
what is cytarabine and what does it treat?
pyrimidine analog that inhibits DNA polymerase; it is used to treat leukemias and lymphomas
what are the toxicities associated with cytarabine?
leukopenia, thrombocytopenia, megaloblastic anemia
name three purine analogs that are used to treat leukemias
6-mercaptopurine, azathioprine, 6-thioguanine
what toxicities are associated with 6-MP, azathioprine and 6-TG?
bone marrow, GI and liver toxicities; 6-MP toxicity exacerbated by allopurinol since it is metabolized by xanthine oxidase (which causes AMP and GMP accumulation by blocking their breakdown to uric acid and negatively feeding back on purine synthesis)
what does dactinomycin treat and what are its associated toxicities?
Wilm’s tumor (childhood kidney cancer), Ewing’s sarcoma (malignant bone tumor that affects children), rhabdomyosarcoma (skeletal muscle cancer that occurs in children)
toxicity=myelosuppresion
what do doxorubicin and daunorubicin treat and what are their associated toxicities?
leukemias, lymphomas and solid tumors
toxicities=dilated cardiomyopathy (Tx with dexrazoxane to prevent cardiotoxicity), myelosuppression, alopecia, toxic to tissues following extravasation
what is bleomycin used to treat and how does it work
testicular cancer, Hodgkin’s lymphoma; it introduces free radicals which cause breaks in DNA strands
what toxicities are associated with bleomycin?
pulmonary fibrosis, skin changes (minimal myelosuppression)
name some alkylating agents used to treat cancers?
cyclophosphamide, ifosfamide, nitrosureas (carmustine, lomustine, semustine, streptozocin), busulfan
what are cyclophoshamide and ifosfamide (cross-link DNA at guanine) used to treat? what are their toxicities?
solid tumors, leukemia, lymphomas and some brain cancers
toxicities=myelosuppression, hemorrhagic cystitis (can partially be prevented by mesna)
what are nitrosureas (carmustine, lomustine, semustine and streptozocin) used to treat? what are their toxicities?
brain tumors;
CNS toxicities like dizziness and ataxia
what is busulfan used to treat and what are its associated toxicities?
CML and bone marrow ablation before transplant
toxicities=pulmonary fibrosis and hyperpigmentation
vincristine and vinblastine are vinca alkaloids that treat what cancers? what are their respective toxicities?
solid tumors, leukemias and lymphomas (by inhibiting microtubule formation)
vincristine causes neurotoxicity and paralytic ileus
vinblastine causes bone marrow suppression
what does paclitaxel treat and what are its toxicities?
ovarian and breast carcinomas
toxicities are myelosuppression and hypersensitivity (allergy)
what are cisplatin and carboplatin used to treat? what are their toxicities?
testicular, bladder, ovary and lung carcinomas
toxicities=nephrotoxicities (prevent with amifostine and chloride diuresis) and acoustic nerve damage
what are etoposide and teniposide used to treat?
what are their toxicities?
solid tumors, leukemias and lymphomas
toxicities=myelosuppresion, GI irritation, alopecia
