ATI RN
Chapter 11 principles of pharmacology Questions
Question 1 of 5
The principle of superposition in designing multiple-dose regimens assumes that
Correct Answer: D
Rationale: The principle of superposition assumes early doses do not affect subsequent doses (D), valid in first-order kinetics where each dose's elimination is independent, summing linearly to predict steady-state (e.g., amoxicillin). Option A suggests nonlinearity (e.g., phenytoin). Option B is zero-order (e.g., ethanol). Option C overestimates; steady-state is ~4-5 half-lives. Option E (original) is unrelated. This linearity simplifies multiple-dose design, ensuring predictable accumulation, critical for maintaining therapeutic levels without toxicity.
Question 2 of 5
A declining growth rate occurs during which of the following phases of bacterial cell growth?
Correct Answer: C
Rationale: A declining growth rate occurs in the stationary phase (C), where bacterial growth slows as nutrients deplete and waste accumulates, balancing birth and death (e.g., E. coli in culture). Lag phase (A) is adaptation, exponential (B) is rapid growth, and death (D) is decline. No original E. This phase mimics chronic infections, influencing antibiotic efficacy (e.g., slower kill rates), critical in pharmacology for understanding bacterial persistence and treatment duration.
Question 3 of 5
Which of the following salts forms an aqueous solution that is alkaline to litmus?
Correct Answer: D
Rationale: Cefazolin sodium (D) forms an alkaline solution, as its conjugate base (cefazolin anion) hydrolyzes water, raising pH (e.g., >7). Sodium chloride (A) is neutral. Benzalkonium chloride (B) and meperidine hydrochloride (C) are acidic from quaternary ammonium or protonated amines. Chlordiazepoxide hydrochloride (original E) is acidic. This basicity, from cephalosporin salts, affects compatibility in IV solutions, critical in pharmaceutical preparation and administration.
Question 4 of 5
Which of the following emissions from the decay of radionuclides is most commonly used in nuclear medicine imaging?
Correct Answer: D
Rationale: Gamma (D) emissions are most used in nuclear medicine imaging (e.g., Tc-99m in SPECT), penetrating tissue for detection without significant damage. X-rays (A) are diagnostic, not decay emissions. Beta (B) and alpha (C) are ionizing, less suitable. Positron (original E) is for PET. Gamma's high energy and low mass enable non-invasive imaging, critical for diagnosing conditions (e.g., myocardial perfusion), balancing sensitivity and safety in nuclear pharmacy.
Question 5 of 5
A 48-year-old-man with end-stage liver disease is hospitalized on the intensive care unit. Review of his blood work reveals elevated liver function tests to five times the normal rate. The patient is receiving multiple intravenous medications. Which of the following medications is likely to be therapeutic for this patient?
Correct Answer: A
Rationale: Epinephrine (A) is likely therapeutic for this patient with end-stage liver disease, as it's minimally metabolized by the liver (via COMT/MAO) and given IV, bypassing hepatic impairment. Erythromycin (B), nifedipine (C), rifampin (D), and verapamil (original E) rely heavily on hepatic metabolism (CYP3A4 or conjugation), risking accumulation with fivefold LFT elevation. Epinephrine's rapid action (e.g., for shock) and renal clearance suit ICU needs, avoiding toxicity in liver failure, where cytochrome P450 activity is compromised, a critical consideration in critically ill patients.