ATI RN
Basic principles of pharmacology Questions
Question 1 of 5
During cisplatin therapy:
Correct Answer: A
Rationale: Pretreatment hydration is mandatory in cisplatin therapy (A), reducing nephrotoxicity by diluting the drug in renal tubules, critical for its safe use in testicular and lung cancers. Dexamethasone and 5HT3 antagonists (B) reduce its high emetogenicity effectively. Visual disturbances (C) are rare; ototoxicity is more common. Magnesium supplements (D) are given for hypomagnesemia from renal loss. Nephrotoxicity is dose-limiting (original E). Cisplatin's DNA cross-linking kills cancer cells, but its renal and auditory toxicity, linked to platinum accumulation, demands aggressive hydration and electrolyte management.
Question 2 of 5
Which of the following terms best describes a drug that blocks the action of epinephrine at its receptors by occupying those receptors without activating them?
Correct Answer: A
Rationale: A pharmacological antagonist (A) best describes a drug that blocks epinephrine's action by occupying its receptors (e.g., beta-blockers like propranolol) without activation, competitively inhibiting the agonist. Partial agonists (B) activate receptors submaximally (e.g., pindolol). Physiological antagonists (C) counteract via different systems (e.g., histamine vs. epinephrine). Chemical antagonists (D) bind the agonist itself (e.g., chelators), not receptors. Noncompetitive antagonists (original E) bind irreversibly, reducing receptor availability. Pharmacological antagonism, central to receptor theory, relies on affinity without efficacy, reversing or preventing epinephrine's effects (e.g., tachycardia), a key concept in managing adrenergic overactivity in conditions like hypertension.
Question 3 of 5
The 'dominant lethal' test involves the treatment of a male adult animal with a chemical before mating; the pregnant female is later examined for fetal death and abnormalities. The dominant lethal test therefore is a test of
Correct Answer: B
Rationale: The dominant lethal test is a test of mutagenicity (B), detecting mutations in male germ cells causing fetal death or abnormalities post-mating, indicating DNA damage (e.g., from alkylating agents). Teratogenicity (A) tests developmental defects from maternal exposure during pregnancy, not paternal. Carcinogenicity (C) assesses tumor formation, requiring long-term studies. Option D is incorrect as it's specific to mutagenesis. Option E (original) is also false. Used in toxicology, this assay identifies genotoxic potential, critical for assessing reproductive risks of chemicals, though it doesn't predict teratogenesis or cancer directly.
Question 4 of 5
Most drug receptors are
Correct Answer: C
Rationale: Most drug receptors are proteins located on cell membranes or in the cytosol (C), such as G-protein-coupled receptors (e.g., beta-adrenergic) or intracellular nuclear receptors (e.g., steroid receptors), mediating specific drug effects. Small molecules (A) like neurotransmitters aren't receptors. Lipids (B) form membranes, not receptors. DNA (D) and RNA (original E) are targets for some drugs (e.g., chemotherapy), not typical receptors. Proteins' structural diversity enables ligand binding and signal transduction, fundamental to pharmacodynamics, distinguishing receptor-mediated effects from non-specific actions like osmosis.
Question 5 of 5
Which equation is used to predict the stability of a drug product at room temperature from experiments at accelerated temperature?
Correct Answer: C
Rationale: The Arrhenius equation (C), k = Ae^(-Ea/RT), predicts drug stability at room temperature by relating reaction rate (k) to temperature (T), using activation energy (Ea) from accelerated studies (e.g., 40°C). Stokes (A) addresses viscosity, Yong (B) is undefined here, Michaelis-Menten (D) is enzyme kinetics, and Hixson-Crowell (original E) models dissolution. This exponential relationship extrapolates shelf life (e.g., 25°C) from higher-temperature degradation rates, critical in pharmaceutical development for ensuring potency and safety over time.