Chemotherapeutic Drugs Flashcards
Cyclophosphamide Class Mechanism Adverse rxns Precautions
Alkylating Agent
Nitrogen mustard that acts as bifunctional alkylating agent. Cross links DNA.
•Prodrug. Tissue selectivity occurs b/c normal tissues can degrade activated intermediates via aldehyde dyhydrogenase and glutathione transferase.
•Adverse rxns – Heart failure, hemorrhagic cystitis (concentrated acrolein metabolite damages bladder epithelium)
•Precautions – Aggressive hydration to avoid bladder toxicity.
Temozolomide Class Mechanism Use Adverse rxns
Alkylating Agent
Prodrug. Methylates DNA mainly at N7 atom of guanine, but anti-tumor effects occur w/ O6 methylation.
•Crosses BBB for brain cancer.
•Adverse rxns – hepatotoxicity. Check LFTs
Carboplatin
Class
Mechanism
Adverse rxns
Platinum compound
•Enters cells via Cu++ transporter. Oxylate moiety displaces water to form reactive molecules that cross-link guanine residues on DNA.
•Adverse rxns – NV (65%, give antiemetic medicines [5HT3 / D2 antagonists, cannabis])
Bleomycin Class Mechanism Adverse rxns Precautions
Anti-Tumor Antibiotic
Copper chelating peptides that binds DNA and forms oxygen free radicals. Opens deoxyribose ring → DNA breaks
•Adverse rxns – Main side effect is pulmonary fibrosis.
•Precautions – do pulmonary function tests to monitor toxicity
Doxorubicin Class Mechanism Adverse rxns Precautions
Anti-Tumor Antibiotic
Intercalates b/w DNA base pairs inhibiting DNA / RNA polymerase. Also stabilizes / inhibits topoisomerase II → DNA breaks
•Adverse rxns – ALL pxs develop some cardiotoxicity (dilated cardiomyopathy). May be due to radical formation. CHF may be fatal. Red discoloration of urine / sweat.
•Precautions – monitor LVEF. Do not exceed 550 mg/m^2 cumulative dose.
5-Fluorouracil (5FU) Class Mechanism Adverse rxns Precautions
Antimetabolite
Pyrimidine analog. Blocks thymidylate synthase → inhibits DNA / RNA synthase.
•Adverse rxns – hand-foot syndrome (derm)
•Precautions – dihydropyrimidine dehydrogenase (DHD) deficiency → toxicity
Gemcitabine Class Mechanism Adverse rxns Precautions
Antimetabolite
Pyrimidine analog. Inhibits DNA polymerase and metabolite is incorporated into DNA → termination. Not confined to S phase.
•Adverse rxns – hepatotoxicity (40%, do LFTs)
•Precautions – Potent radiosensitizer. Don’t use w/ radiotherapy.
Methotrexate Class Use Mechanism Adverse rxns Precautions
Antimetabolite
Txs cancer, RA, and psoriasis.
Folic acid analog that inhibits DHFR (dihydrofolate reductase) → reduced purine synthesis.
•Adverse rxns – toxic epidermal necrolysis (TEN), Stevens-Johnson syndrome, oral / GI ulcers, hepatitis, pancytopenia.
•Precautions – NSAIDs reduce secretion → toxicity
Vincristine Class Mechanism Adverse rxns Precautions
Antimitotic agent
“Spindle poison” that binds to tubulin monomer, disrupting microtubule assembly → cell arrests in M phase → inhibits cell division.
•Adverse rxns – neurotoxicity w/ stocking and glove parasthesia, CN damage, paralysis. Reversible alopecia, even w/ continued tx.
•Precautions – intrathecal administration is fatal.
Paclitaxel Class Mechanism Adverse rxns Precautions
Antimitotic agent
Spindle poison that stabilizes assembly of microtubules, making them extremely stable and nonfunctional → arrests M phase.
•Adverse rxns – Stocking and glove neuropathy (62%), ECG abnormalities
•Precautions – Pretreat w/ H1 / H2 antagonist or glucocorticoid to reduce likelihood of hypersensitivity rxns
Etoposide
Class
Mechanism
Topoisomerase inhibitor
Stabilizes topoisomerase II → strand breaks → apoptosis.
Irinotecan Class Mechanism Adverse rxns Precautions
Topoisomerase inhibitor
Prodrug. Stabilizes topoisomerase I → strand breaks.
•Adverse rxns – Cholinergic syndrome from AchE inhibition (reverse w/ atropine)
•Precautions – Genetic defect may increase risk of neutropenia. Test beforehand.
Bevacizumab Class Mechanism Adverse rxns Precautions
Monoclonal antibody
Humanized IgG. Inhibits VEGF from stimulating receptor → inhibits angiogenesis.
•Adverse rxns – CV (HTN, thromboembolic events), proteinuria, infusion reactions – headache, fever, rash
•Precautions – monitor blood pressure for first 2-3 weeks
Cetuximab Class Mechanism Adverse rxns Precautions
Monoclonal Antibody
Human-mouse chimeric IgG. Directed against EGF receptor → inhibits growth and causes apoptosis
•Adverse rxns – DERM (90%, acneiform rash, pruritis, etc). Infusion reactions.
•Precautions – monitor for anaphylactic rxn, tx w/ epinephrine
Rituximab Class Use Mechanism Adverse rxns Precautions
Monoclonal antibody
Human-mouse chimeric IgG. Tx non-Hodgkin’s lymphoma.
•Binds CD20, which is a B lymphocyte antigen → B cell lysis via cytotoxic immune cells.
•Adverse rxns – Life threatening events in 57% of pxs (CV, GI, renal toxicity). Infusion rxn to 80% of pxs
•Precautions – All pxs should receive diphenhydramine, acetaminophen, and possibly corticosteroids as premedication
