ATI RN
Basic pharmacology principles Questions
Question 1 of 5
A hospitalized patient with systemic infection is receiving intravenous antibiotics. He also has hepatic and renal insufficiency. After receiving medications for 5 days, he is found by nursing staff to be jaundiced. Drug toxicology profile is obtained and indicated drug levels of 10 times the acceptable value. Which of the following drug administration schemes is most likely to explain this situation?
Correct Answer: A
Rationale: Continuous IV infusion (A) most likely explains the toxic drug levels (10× normal) and jaundice in this patient with hepatic and renal insufficiency. Constant delivery (e.g., vancomycin) overwhelms impaired clearance, causing accumulation over 5 days. Weekly (B) or twice-weekly (original E) injections allow recovery periods, less likely to build up. Daily (C) or twice-daily (D) bolus dosing risks peaks but less sustained excess than infusion. In hepatic/renal failure, reduced metabolism/excretion (e.g., bilirubin rise causing jaundice) amplifies toxicity, highlighting infusion's risk in such patients, requiring dose adjustment.
Question 2 of 5
A 15-year-old boy who has diabetes and is insulin dependent is brought to the emergency department after collapsing at a baseball game. His blood sugar is $463 \mathrm{mg} / \mathrm{dL}$ by finger stick. Which of the following routes of administration would be most efficacious for medications to bring the blood sugar down?
Correct Answer: B
Rationale: Intravenous (B) is most efficacious for insulin in this hyperglycemic crisis (463 mg/dL), delivering it directly to the bloodstream for rapid glucose uptake (within minutes), critical in diabetic ketoacidosis. Intramuscular (A) and subcutaneous (D) are slower (15-30 min onset). Oral (C) isn't viable for insulin (degraded by GI). Sublingual (original E) is impractical. IV's immediacy, bypassing absorption delays, ensures fast correction, vital in emergencies to prevent organ damage, a cornerstone of acute diabetes management.
Question 3 of 5
A 19-year-old female has a history of absence seizures. She currently takes ethosuximide to control her symptoms. The process of eliminating this drug involves multiple steps of metabolism followed by excretion. Many organs take part in both metabolism as well as excretion of drugs. Which of the following describes a step of metabolism?
Correct Answer: A
Rationale: Acetaminophen glucuronidation by enterocytes (A) is a metabolic step, a phase II reaction conjugating the drug for excretion, occurring in gut and liver. Digoxin transport (B) and pancuronium filtration (D) are excretion, not metabolism. Ethanol exhalation (C) is elimination via lungs, not transformation. Ethosuximide's hepatic metabolism (e.g., hydroxylation) parallels this, with enterocyte glucuronidation enhancing polarity, critical for clearance, distinguishing metabolism from mere transport in pharmacokinetics.
Question 4 of 5
A 21-year-old man presents to his primary care physician complaining of a single, painless ulcer on his penis, which he first noticed a few days ago. He admits to multiple sexual partners. You want to treat him for syphilis with penicillin G, but his history includes an itchy rash following amoxicillin treatment as a child. What must first occur in the body for a penicillin to become allergenic?
Correct Answer: B
Rationale: Penicillin becomes allergenic by binding to a larger molecule (e.g., proteins) (B), forming a hapten-carrier complex the immune system recognizes as foreign, triggering IgE-mediated Type I hypersensitivity (e.g., rash). First-pass metabolism (A) isn't required. Simple exposure (C) needs sensitization first. Option D is false; penicillin's allergenicity is IgE-driven. This conjugation, critical in syphilis treatment (penicillin G), necessitates allergy screening, as prior amoxicillin reaction suggests risk, guiding alternative therapy (e.g., doxycycline).
Question 5 of 5
The following drugs exert their effects by binding to receptors and mimicking the effects of the endogenous ligand (i.e. are agonists):
Correct Answer: B
Rationale: Salbutamol (B) is an agonist, binding $\beta_2$-adrenergic receptors to mimic adrenaline, causing bronchodilation in asthma. Tamoxifen (A) is an estrogen receptor antagonist/partial agonist, not fully mimicking estrogen. Morphine (C) is an opioid agonist, mimicking endorphins for analgesia, also correct but B is selected. Cetirizine (D) is an Hâ‚ antihistamine antagonist, blocking histamine. Lisinopril (original E) inhibits ACE, not a receptor agonist. Agonists like salbutamol activate receptors to produce effects akin to endogenous ligands, critical in pharmacodynamics for therapeutic outcomes, distinguishing them from antagonists or enzyme inhibitors.