Antineoplastics Flashcards
Mechlorethamine: (explain/give the following) a. Class b. Mechanism c. Pharmacokinetics d. Therapeutic use e. adverse effects
a. Alkylating agent (nitrogen mustard) b. Type I. Bifunctional alkylating agent: produces cross-links in DNA. c. IV. No CNS penetration. Highly reactive. Disappears from blood in seconds to minutes d. Hodgkin’s and non-hodgkin’s lymphoma e. nausea/vomiting, myelosuppression, mild alopecia
Name three alkylating agent antineoplastic drugs
- mechlorethamine (nitrogen mustard) 2. cyclophosphamide (nitrogen mustard) 3. carmustine (BCNU) (nitrosourea)
Name two vinca alkaloid antineoplastic drugs
- Vinblastine 2. Vincristine
Name five antimetabolite antineoplastic drugs
- methotrexate (MTX) 2. 5-fluorouracil (5-FU) 3. cytarabine (Ara-C) 4. mercaptopurine (MCP) 5. hydroxyurea
Name one taxane antineoplastic drug
- Paclitaxel
Name four antiestrogenic antineoplastic drugs and the sub-class of each
- temoxifen (TAM) - nonsteroidal antiestrogen 2. letrozole - aromatase (CYP19) inhibitor 3. leuprolide - GnRH analog 4. flutamide - nonsteroidal antiandrogen
Name one corticosteroid antineoplastic drug
- prednisone
Name one atypical alkylating agent antineoplastic drug
- procarbazine
Name one metal complex used as an antineoplastic drug
- cisplatin (platinum coordination complex)
Name one monoclonal antibody used as an antineoplastic drug
- trastuzumab (Herceptin)
Name two antibiotic agents used as antineoplastic drugs
- doxorubicin 2. bleomycin (BLM)
Name one epipodphyllotoxin used as an antineoplastic drug
- etoposide (VP16)
Name one BRM used as an antineoplastic drug
- filgrastim
Mechlorethamine: mechanism of action
Type I (nitrogen mustard). Bifunctional alkylating agent: produces cross-links.
Cyclophosphamide: mechanism of action
Type III (nitrogen mustard). Prodrug activated in liver by CYP450 → active compound phosphoramide mustard acts as akylating agent. Acrolein (byproduct) causes bladder toxicity
Mechanism of action: carmustine (BCNU)
alkylating agent. produces cross-links in DNA
Mechanism of action: Methotrexate
antimetabolite:
Binds to DHFR → blocks formation to FH4 → blocks purine and pyrimidine synthesis
Mechanism of action: 5-fluorouracil (5-FU)
antimetabolite
Pyrimidine analog → activated to FUTP → inhibits RNA synthesis
Pyrimidine analog → activated to FdUMP → interferes with thymidylate synthase → inhibit DNA synthesis
Mechanism of action: cytarabine (Ara-C)
antimetabolite
Pyrimidine (cytadine) analog → competes for phosphorylation of cytidine → also competes with cytidine for incorporation into DNA → causes chain termination
Mechanism of action: mercaptopurine
antimetabolite
Purine analog → converted in cells (by HGPRT) to ribonucleotide that inhibits purine synthesis. Further converted and misincorporated into DNA and RNA
Mechanism of action: hydroxyurea
antimetabolite
Substituted urea → inhibits ribonucleotide reductase → blocks conversion to dNTPs → prevents DNA synthesis → arrests cell at G1-S interface
Mechanism of action: vinblastine
vinca alkaloid
Binds tubulin → prevents formation of microtubules and mitotic spindle
Mechanism of action: vincristine
vinca alkaloid
Binds tubulin → prevents formation of microtubules and mitotic spindle
Mechanism of action: paclitaxel
taxane
Binds tubulin beta-subunity → enhances assembly and stability of microtubules → arrests cells in late G2 phase (G2/M interface)
Can also interfere with DNA repair – intensifying effect of cisplatin or cyclophosphamide
Mechanism of action: doxorubicin
Antibiotic
Antitumor antibiotic (similar to tetracyclines) → intercalates in DNA (distorts helix). Also causes lipid peroxidation and ROS generation. Also binds DNA topoisomerase II → prevents resealing of DNA strand breaks
Mechanism of action: bleomycin (BLM)
Antibiotic
Iron-containing glycopeptide that binds to DNA → causes oxidative-like damage to DNA → DNA strand breaks (single and double)
Mechanism of action: etoposide (VP16)
Epipodphyllotoxin
Irreversible stabilizes DNA-topoisomerase II complexes → results in dsDNA breaks that cannot be repeaired → arrests cell in late G2 phase (G2/M interface)
Mechanism of action: fligrastim (G-CSF)
BLM
Granulocyte colony stimulating factor → promotes neutrophil progenitors → expands absolute population of neutrophils → counteracts the effects of chemotherapy-induced neutropenia
Mechanism of action: trastuzumab (Herceptin)
Monoclonal antibody
Monoclonal antibody → binds HER2 receptor (human epidermal growth factor receptor 2) → blocks proliferation of cells (25-30% of metastatic breast cancers express HER2R
Mechanism of action: cisplatin
Metal complex
Platinum coordination complex → hydrolysis yields activated species which cross-links DNA → inhibits transcription, repair, protein recognition → produces apoptosis
Also covalently binds thioredoxin reductase (TrxR – overexpressed by many cancers) → directly promotes apoptosis
Mechanism of action: procarbazine
atypical alkylating agent
activated in vivo by liver to methylating agent → chromosomal damage
Mechanism of action: prednisone
Corticosteroid
Bind steroid receptors → modulate cell growth, including: arrest cells at G1, depress growth gene expression, induce nucleases (promote cell lysis)
Mechanism of action: tamoxifen (TAM)
Antiestrogenic - non-steroidal
Nonsteroidal antiestrogen → competitively blocks estrogen receptors in breast tissue. → cells halt at G0/G1 interface. Also elevates sex hormone-binding globulin → decreases free estradiol levels
Off-label use: estrogen agonist in bone tissue → may prevent post-menopausal osteoporosis
Mechanism of action: letrozole
Antiestrogenic
Aromatase (CYP19) inhibitor → binds heme domain → blocks conversion of androgens to estrogens → prevents stimulation of ER+ cells
Mechanism of action: leuprolide
Antiandrogenic
GnRH analog → initially stimulates LH and FSH → testosterone surge (and disease flare) → LH/FSH burnout after 2-4 wks → decrease testosterone to castration levels
Mechanism of action: flutamide
Antiandrogenic
Nonsteroidal antiandrogen → blocks androgen receptors
Therapeutic use: mechlorethamine
Hodgkin’s and non-Hodgkin’s lymphoma
Therapeutic use: cyclophosphamide
Broad spectrum anti-cancer (most widely used alkylating agent)
Therapeutic use: carmustine (BCNU)
Brain tumors
multiple myeloma
melanoma
Therapeutic use: methotrexate
Acute lymphblastic leukemia (ALL)
Choriocarcinoma
Therapeutic use: 5-fluorouracil (5-FU)
Broad spectrum: stomach, colon, pancreas, overy, head, neck, breast, bladder. Basal cell carcinoma.
**GI and breast are most common applications**
Therapeutic use: cytarabine (Ara-C)
Acute leukemias
Acute myelocytic leukemia (AML)
Lymphomas
Head and neck cancer
Therapeutic use: mercaptopurine
Acute leukemias
Chronic granulocytic anemia