Antineoplastic Drugs Flashcards
Methotrexate
- Mechanism of Action
- Treatment
- Resistance
- Toxicity (3)
- Inhibits Dihydrofolate Reductase
- Widespread treatment (Leukemia, Sarcoma, etc.)
- DHFR alterations/increased expression
- Bone marrow suppression, Lung infections, Nephrotoxicity
5-fluorouracil
- Mechanism of Action
- Treatment
- Toxicity
- Metabolized into FUTP, FdUMP, FdUTP
FdUMP Inhibits Thymidylate Synthase
FUTP and FdUTP are incorporated into RNA and DNA, respectively
***Given in combination***(rarely used alone)
- Widespread Treatment (Breast, Head, Neck, GI)
- GI Ulcers, Bone Marrow Suppression
Capecitabine
- Mechanism of Action
- Treatment
- Toxicity
- Prodrug of 5-FU (So same as 5-FU)
Cyarabine (ara-C)
- Mechanism of Action
- Treatment
- Resistance
- Toxicity
- Ara-C is converted to Ara-CMP by deoxycytidine kinase, Ara-CMP is incorporated into DNA which inhibits DNA polymerase and halts DNA elongation
- ***Acute Myelogenous Leukemia*** (AML) and Hematologic Malignancies (No solid tumors)
- Loss of Deoxycytidine Kinase, reduced transport in, upregulation of Cytidine Deaminase
- Cerebellar Syndrome (dysarthria, nystagmus, ataxia), Kidney/Liver Dysfunction, Advancing Age, Myelosuppression
Gemcitabine
- Mechanism of Action
- Treatment
- Resistance
- Deoxycytidine Kinase converts Gemcitabine into 2,2-difluorodeoxycytidine, which: 1) is incorporated into DNA and 2) inhibits ribodnucleotide reductase
- Treats a Wide Range of cancers (Pancreatic, NSC Lung, Ovarian, Bladder)
- Decreased Deoxycytidine Kinase, Increased Deoxycytidine
6-Thioguanine (6-TG) and 6-Mercaptopurine (6-MP)
- Mechanism of Action
- Treatment
- Resistance
- Toxicity
- Converted to Thio-IMP and Thio-GMP by HGPRT (enzyme) and both 1) inhibit purine synthesis and are 2) incorporated into DNA
- ***Acute Lymphoblastic Leukemia*** (ALL)
- Decreased HGPRT activity
- Decreased TPMT activity (due to polymorphisms)
***TPMT inhibits 6-MP***
Fludarabine
- Mechanism of Action
- Treatment
- Resistance
- Deoxycytidine Kinase activates to triphosphate form, which is incorporated into DNA/RNA and inhibits 1) DNA polymerase, 2) Ribonucleotide Reductase, 3) RNA function (i.e. translation to proteins)
- ***Chronic Lymphocytic Leukemia*** (CLL)
- Decreased Deoxycytidine Kinase activity, Drug Efflux
Clabridine
- Mechanism of Action
- Treatment
- Resistance
- Deoxycytidine Kinase activates to tri-phosphate form, which is incorporated into DNA (strand breaks) and inhibits Ribonucleotide Reductase (RNR)
- ***Hair Cell Leukemia***
- Decreased Deoxycytidine Kinase activity, Drug Efflux, Increased RNR expression
Mechlorethamine
- Mechanism of Action
- Treatment
- Administered in combination with Vincristine, Procarbazine, and Prednisone (a combination chemo regimen called MOPP)
- MOPP is used to treat ***Hodgkin’s Lymphoma***
Cyclophosphamide
- Mechanism of Action
- Treatment
- Toxicity
- Liver Cytochrome P450 Oxidase converts to active form Aldophosphamide, which causes DNA cross-linking and strand breakage
- Solid Tumors/Hematological Malignancies
- ***Hemorrhagic Cystitis*** (if Aldophosphamide is converted to acrolein - 5-10% of pts), Myelosuppression, Nausea, Vomiting
- Mechlorethamine
What drug can lead to hemorrhagic cystitis, and what compound prevents this from happening/through what mechanism?
- Cyclophosphamide
- Prevented with Mesna, which inactivates acrolein
Carmustine (BCNU)
- Mechanism of Action
- Treatment
- Toxicity
- Lipophilic (crosses BBB) and leads to DNA cross-linking and Strand Breakage
***Carmustine Wafers***
- ***Brain Tumors, Hodgkin’s/Non-Hodgkin’s Lymphoma***
- Myelosuppression
Mnemonic: BrainCancerNon-Hodgkin’s
General Adverse Effects of Alkylating Agents
(e.g. Cyclophosphamide, Mechlorethamide, Carmustine (BCNU))
(4)
- Mutagenic, Teratogenic, and Myelosuppressive
- Dose-limiting toxicity = Bone Marrow Suppression and Damage to Intestinal Mucosa
- Can cause Leukemia (peak at approx 4 yrs. post therapy)
-
Blistering of veins with repeated use
(i. e. Vesicant properties)
Resistance to Alkylating Agents
(e.g. Cyclophosphamide, Mechlorethamide, Carmustine (BCNU))
(4)
- Inactivation by Glutathione and other nucleophiles (increased Glutathione production)
- Reduced uptake
- Accelerated DNA repair
- Increased expression of MGMT (O6-methylguanine-DNA methyltransferase)
- Removes alkyl groups from guanine before cross-links form (preventing further DNA damage)
Platinum Compounds (Non-Classical Alkylating Agents)
- Mechanism of Action
- Treatment
- Drugs (3)
- Platinum group allows for DNA cross-linkages to form (specifically targets nucleophilic center (Guanine-N7)
- Widespread Treatment
- Cisplatin** (1st gen.), Carboplatin** (2nd gen.), Oxaliplatin** (3rd gen.)
Cisplatin
- Key Side Effects
Peripheral motor and sensory neuropathy
Tinnitus and high-frequency hearing loss
Nephrotoxicity (reduced by IV saline)
Anaphylactic-like reactions (Hypersensitivity Reactions)
Carboplatin
- Key Side Effects
Dose-limiting toxicity is Myelosuppression
Anaphylactic-like reactions (Hypersensitivity Reactions)
Procarbazine
- Class
- Treatment
- Non-classical alkylating agents (MoA –> DNA cross-linking/damage)
- Hodgkin’s Disease
Dacarbazine
- Class
- Treatment
- Non-classical alkylating agents (MoA –> DNA cross-linking/damage)
- Component of curative combination therapy for Hodgkin’s Lymphoma
-Melanomas and Sarcomas
Temozolomide
- Class
- Treatment
- Non-classical alkylating agents (MoA –> DNA cross-linking/damage)
- Glioblastomas and Metastatic Melanoma
Vinblastine
- Class
- Mechanism of Action
- Toxicity
- Antimicrotubule Agent
- Prevents microtubules from forming
- Significant Myelosuppression