Anti-neoplastic drugs Flashcards
What does the therapeutic window for a anticancer drug look like?
Very small
When you combine cancer drug what should NOT be done?
Should not combine ones with the same actions and the same toxicities
Why are multiple cycles of an anti cancer drug needed?
Only kills 99% of the cells and the 1% can grow back quickly
Which cells are the most susceptible to chemotherapy?
Rapidly growing cells
Which cancer drugs enter at the M phase of the cell cycle?
Vincristine
Vinblastine
Vinorelbine
Paclitaxel
Which cancer drugs enter at the S phase of the cell cycle?
Cytarabine
6-mercaptopurine
Methotrexate
What are the nitrogen mustards? *
Mechlorethamine
Cyclophosphamide
Ifosfamide
What are the platinum complexes? *
Cisplatin
What are the nitrosoureas?
Lomustine
Carmustine
What are the triazenes?
Dacarbazine
Temozolomiden
What are the methylhydrazines?
Procarbazine
What are the alkyl sulfonate? *
Busulfan
What does cross linked DNA do?
Interferes with DNA replication and causes cell cycle arrest
What chemotherapeutic drugs are alkylating agents?
Nitrogen mustards Platinum complexes Nitrosoureas Triazenes Methylhydrazine Alkyl sulfonate
What is the mechanism of action for alkylating agents? *
Cross links the DNA
Mechloresthamine (Mustargen) *
Most reactive nitrogen mustard
Pharm: unstable, given IV immediately after being made up
Toxic: N&V, bone marrow, tissue damage w/ extravesation
Cyclophosphamide (Cytoxan, Neosar) *
Pharm: well absorbed orally, prodrug which must be converted by liver cytochrome P450 to active metabolite
Toxic: N&V, cardiotoxic, hemorrhagic cystitis, bladder burn, hematuria, bone marrow toxic
What is the mechanism of platinum complexes? *
Covalent crosslink with GG base pairs to bend DNA
Cisplatin (Platinol): Pharmacology *
IV, 90% bound to plasma protein, concentrates in liver, kidney, intestine, ovary and excreted in urine
Cisplatin (Platinol): Toxicity *
N&V, hypersensitivity rashes, renal damage (hydrate to stop), ototoxicity w/ high frequency hearing loss + tinnitus, peripheral sensory neuropathy and bone marrow depression
Busulfan (Busulfex, Myleran) *
Pharm: Oral, half life 2/3 hrs
* Toxicity: N&V, bone marrow depression (stem cells), pulmonary infiltrates and fibrosis
What is the mechanism of antimetabolites?
Block formation of DNA
Form abnormal DNA
Cell cycle dependent
Inhibit protein synthesis
What are the antimetabolites?
Methotrexate, Asparaginase Fluorouracil, Capecitabine, Cytarabine, Mercaptopurine
What is the mechanism for methotrexate?
Analog of floic acid
Competitive inhibitor of dihydrofolate reducatse
Blocks dTMP synth which is required for DNA synth
Inhibits the folate-dependent enzymes of de novo purine and thymidylate synth
Methotrexate *
Pharm: Oral, IV, IM, Intrathecally, majority excreted unchange in urine
* Tox: Alopecia, N&V, diarrhae, fever, hepatic necrosis, hypersenitivity rxns, oral + Gi ulcers, bone marrow depression, pulmonary infiltrates and fibrosis
What is the mechanism for fluorouracil?
Converted to fraudulent F-dUMP
Fraud F-dUMP forms a covalent complex with thymidylate synthase and methylene tetrahydrofolate
Results in inhibition of DNA synth
Fluorouracil
Pharm: IV, distributes through body and brain, metabolized in liver, short half life (10-15 min)
* Tox: severe ulceration of oral + Gi mucosa, N&V, diarrhea, alopecia, bone marrow depression
Capecitabine (Xeloda)
Pharm: converted to 5-FU by an thymidine phosphorylase which is highly expressed in solid tumors, oral admin
What is the mechanism of Cytarabine (cytosine arabinoside)?
2’-deoxycytidine analog; phosphorylated to aracytidine triphosphate
2’-hydroxyl trans tp 3’hydroxyl hunders rotation of base and inhibits DNA chain elongation
Inhibits DNA pol
How does DNA chain elongation work?
The OH group of the 3’ carbon of the sugar of one nucleotide forms an ester bond to the phosphate of another nucelotide eliminating a molecule of water
Next nucleotide added to 3’ end
Cytarabine (ctosine arabinoside)
Pharm: IV, rapidly inactivated by cytidine deaminase in GI and liver
* Tox: bone marrow depression, oral ulcers, hepatic damage, N&V, diarrhea, anaphylaxis, fever, pulmonary edema, high does = sudden respiratory distress and CNS toxicity
What is the clinical use of cytarabine?
Acute myelocytic leukemia (AML)
Lymphoblastic leukemia (ALL)
Chronic myelogenous leukemia (CML)
What is the mechanism of 6-mercaptopurine?
Converted to 6-mercaptopurine ribose phosphate; inhibits purine (guanine) synth
Triphosphate form can be incorperated into DNA resulting in DNA strands and breaks
Used for leukemia in children
6-mercaptopurine
- Pharm: oral bioavailability - 5-37%, IV half life 50 min, metabolized in liver
- Tox: bone marrow depression, N&V (25%), hepatic enzyme elevate (33%)
If a pt is receiving oral doses of 6-mercaptopurine how much should it be reduced to if the pt is also receiving Xanthine oxidase inhibitors (allopurinol)? *
75%
What are the thymine pyrimidine antimetabolites?
Fluorouracil (5-FU), capecitabine, floxuridine, idoxuridine
What are the cytosine pyrimidine antimetabolites?
Cytarabine (Ara-C, cytosine arabinoside), 5-azacytidine, decitabine, gemcitabine
What are the guanine purine antimetabolites?
6-mercaptopurine, azathioprine
What are the adenine purine antimetabolites?
Fludarabine, cladrabine, pentostatin
What is a purine antimetabolite (non-specified)?
Methotrexate
What are the three phosporylation events of a nucleoside analog?
First is rate-limiting nucleoside kinase
Triphosphorylated analongue can incorporate into DNA/RNA and/or inhibit enzymes
Active nucleoside analogues catabolized by 5’-nucleotidase and deaminase
What is the mechanism of Asoarginase Erwinia chrysanthemi (Erwinaze)? *
Hydrolyze asparagine to aspartic acid and ammonia
Some lymphoid malignancies require L-asparagine from plasma
Inhibits protein synth
Asoarginase Erwinia chrysanthemi (Erwinaze)
Pharm: IV
* Tox: risk of anaphylaxis, minimal effect on bone marrow and GI mucous, hyperglycemia, clotting deficiency
What is the clinical use for Asoarginase Erwinia chrysanthemi (Erwinaze)?
Acute lymphoblastic leukemia
Microtubule inhibitors; taxanes
Paclitaxel
Docetaxel
What is the shared mechanism of paclitaxel and docetaxel? *
Taxanes stabilize or freeze polymerized microtubules
Block mitosis metaphase arrest
Paclitaxel and docetaxel
Pharm: IV, metabolized in liver
* Tox: bone marrow toxicity, peripheral sensory neuropathy (dose limited) and hypersensitivity rxn
What is the mechanism of anthracycline antibiotics?
Intercalates into DNA and blocks the resealing action of topoisomerase II, generates free radical
What are the toxicities of anthracycline antibiotics?
Acute cardiac toxicity; arrhythmias ST & T wave alterations
Chronic cardiac toxicity; cardiomyopathy leading to congestive heart failure unresponsive to digitals related to total cumulative dose
Severe local tissue damage
Topoisomerase inhibitors; Anthracycline antibiotics
Doxorubicin
What are the topoisomerase inhibitors?
Anthracycline antibiotics
Dactinomycin
Etoposide
Camptothecins
Topoisomerase inhibitors; Camptothecins
Irinotecan
What is the mechanism of topoismerase inhibitors?
Inhibits resealing of nicked DNA
What is the mechanism of doxorubicin? *
Intercalates into DNA and blocks the resealing action of topoisomerase II
Doxorubicin (Adriamycin)
Pharm: rapid infusion IV, distributes widely except to CNS, metabolized in liver and excreted in bile
* Tox: N&V, red urine (not hematuria), severe local tissue damage with extravasation, diarrhea, fever, transient ECG changes, ventricular arrhythmia, cardiotoxicity
What is the mechanism for the toxicity of Doxorubicin?
Free radical damage: doxorubicin + Fe(+2) can generate hydroxyl radicals from peroxide
Dexrazoxane: to protect from cardiotoxicity and treat extravastion from IV doxorubicin
What is the mechanism if irinotecan (camptosar)? *
Blocks the resealing action of topoisomerase I
Irinotecan (camptosar)
Pharm: IV
* Tox: dose limiting myelosuppression and severe GI toxicity life-threatening
Limited use of UGT1A1*28 polymorphism of Uridine disphoate
What is the therapeutic use of irinotecan?
Metastatic and recurrent colon cancer; small cell lung cancer
What is the free radical generator?
Bleomycin (blenoxane) - mixture of 2 cooper chelating glycopeptide antibodies
What is the mechanism of bleomycin? *
DNA-bleomycin-Fe(2+) complex forms DNA-bleomycin-Fe(2+) interacts with oxygen Forms superoxide (O2-) and hydroxyl free (OH-) radicals Radials produce DNA breaks (DNA fragmentation) DNA repair mechanism determine cytotoxicity
Bleomycin
Pharm: IV, subQ or IM, localized to skin, lymph, lung, lymphatic and peritoneum tissue, excreted in urine
* Tox: N&V, fever, anaphlazis and phlebitis at injection site, degraded by hydrolysis which is low in lungs - pulmonary fibrosis, ulcers, hyperpigment
What are the hormone inhibitors?
Aromatase inhibitors
Hormone analogs
What are the aromatase inhibitors
Exemestane
Letrozole
Anastrozole
What is the mechanism of aromatase inhibitors?
Block the conversion of androgens to estrogen
What is the pharm and tox of aromtase inhibitors?
Oral
Musculoskeltal pain, headache, joint pain, hot flashes, fatigue, difficulty breathing, bone density, hot flashes
What is the therapeutic use for aromatase inhibitors?
Breast cancer, postmenopausal women
What are the hormone analogs?
Goserelin acetate
Megestrol acetate
What is the mechanism of goserelin acetate (Zoladex)?
Decapeptide analong of LHRH prolonged adminstration inhibits gonadotropin secretion = dec extradiol
What are the side effects of goserelin acetate?
Headache, hot flashes, emotional lability, depression, vaginitis
What is the therapeutic use for goserelin acetate?
Prostate cancer, advanced breat cancer in pre/peri-menopausal women
What is the mechanism for pamidronate disodium (Aredia)? *
Synthetic bisphosphate pamidronate
adsorb to calcium phosphate crystals in bone, blocks their dissolution by inhibiting osteoclast-mediated bone resorption
What are the side effects for pamidronate disodium?
Fever, severe joint, bone and muscle pain, seizure
What are the tyrosine kinase inhibitors?
Monoclonal antibodies
Chemical agents
What are the monoclonal antibodies?
Trastuzumab
Bevacizumab
Cetuximab
Rituximab
What are the chemical agents?
Tamoxifen
Imatinib
Suffix for chimeric antibodies
-ximab
Suffix for humanized antibodies
-umab
Suffix for nonhuman host antibodies
-omab
What is the mechanism for monoclonal antibodies?
Antibody-dependent cell-mediated cyotoxicity
Complement-mediated cytotoxicity
Direct induction of apoptosis
What is the mechanism for trastuzumab? *
Recombinant DNA-derived humanized monoclonal antibody that recognizes the HER2 receptors that can be overexpressed on breast cancer cells
HER2 receptor overexpression causes cells to grow, divide and multiply
What is the therapeutic use for trastuzumab? *
HER2 overexpressing metastatic breast cancer (25%)
What is the toxicity for trastuzumab? *
Weakening for the heart muscle, congestive heart failure, anemia
What is the mechanism for bevacizumab? *
Humanized monoloncal antibody that reconginzes vascualr-endothelial growth factor and inhibits ineteraction of VEGF with its receptors
What is the therapeutic use for bevacizumab? *
Treatment for metastatic colorectal cancer
What is the toxicity of bevacizumab? *
Proteinuria, hypertension, congestive heart failure, gastrointestinal perforations, pulmonary hemorrhage
What is the mechanism of cetuximab? *
Monoclonal antibody that binds to the epidermal growth factor receptor (EGFR or HER1)
Block binding of epidermal growth factor and other ligands (TGF-a) to the receptor on normal and tumor cells
Inhibits cell growth and induces apoptosis
What is cetuximab used for? *
Metastatic colorectal cancer
Resitricted in pts w/ wildtype KRAS
Cetuximab
Pharm: give IB every 2 weeks
Tox: severe infusion rxn, acneiform rash, hypomagnesemia
What is the side effect of EGFR inhibitors?
Severe acneiform rash/eruption
What is Rituximab?
Chimeric human-mouse monoclonal that recognizes CD20
What is the mechanism of rituximab?
Complement-mediated cytoxicity
Antibody dependent cell mediated cytotoicity
Induction of apoptosis in malignant lymphoma cells
What is the clinical use for rituximab?
First line of treatment for CD20 B-cell malignancies
Replased B-cell non-hodgkin’s lymphoma
Chronic lymphocytic leukemia
What are the side effects of rituximab? *
Infusion rxns, fever, chills, lymphopenia, infection, asthenia, hep B reactivation, leukoencephalopathy
What are immunoconjugates?
Attach radioisotope to monoclonal antibody (gamma or beta)
Antibody binds target
Cytotoxic ionizing radiation delivered to antigen expressing cells
What are the tyrosine kinase inhibitors?
Tamoxifen Lapatinib Imatinib Nilotininb Ponatinib
What is the mechanism of tamoxifen? *
Binds estrogen receptor
Competitive inhibitor of estradiol binding the estrogen receptor
Tamoxifen (nolvadex)
Pharm: oral, metabolized in liver w/ active metabolites (N-desmethyltamoxifen and trans 4-hydroxytamoxifen
* Tox: N&V, hot flush, vag discharge, endometrial cancer, venous thrombosis + pulmonary emboli, stroke
What is the therapeutic use for tamoxifen? *
Estrogen-dependent breast cancer
What is the side effect to tamoxifen?
Reduced serum cholesterol and reduced maintenance of bone density
What is the mechanism of lapatinib? *
HER2 and EGFR (HER1) inhibitor
What is the mechanism of imantinib? *
Inhibitor of constitutively active Bcr-Abl tyrosine kinase (product of the Philadelphia chromosome)
Blocks the ATP binding site on the kinase.
What is the mechanism of nilotinib (tasigna)? *
Inhibitor of Bcr-Abl tyrosine kinase
Binds to and stabilizes the inactive conformation of the kinase domain of the Abl protein of the Bcr-Abl fusion protein
Inhibits platelet-derived growth factor receptor (PDGF-R) and c-kit
What is the mechanism for ponatinib? *
Inhibits unmutated and all mutated forms of Bcr-Abl, including T315I, the highly drug therapy-resistant missense mutation of Bcr-Abl.
Inhibits other tyrosine kinases associated with VEGFRs and FGFRs
Inhibits the tyrosine kinase receptor TIE2 and FMS-related tyrosine kinase receptor-3 (Flt3)
Tretinoin toxicity *
“Retinoic acid syndrome”
(fever, dyspnea, weight gain, pulmonary infiltrates, pleural or pericardial effusions), onset 2-21 days, potentially lethal
What is the target of tretinoin? *
Acute promyelocytic leukemia (APL), high rate complete remission as a single agent
Arsenic trioxide toxicity *
Atrial or ventricular arrhythmias - lengthening of QT interval on ECG (40% patients)
What is the target of arsenic troxide (ATO)?
Relapsed acute promyelocytic leukemia (APL), complete responses in >85% patients