ATI RN
Chapter 26 principles of pharmacology Questions
Question 1 of 5
A patient receives long-term, high-dose therapy with a sulfonamide. After approximately 3 weeks of therapy, the patient has a low-grade fever, rash, and muscle and joint pain. Which type of hypersensitivity accounts for these symptoms?
Correct Answer: C
Rationale: Type III hypersensitivity (C) accounts for these symptoms after 3 weeks of sulfonamide therapy, a serum sickness-like reaction from immune complexes depositing in tissues, causing inflammation (fever, rash, arthralgia). Type I (A) is immediate (e.g., anaphylaxis). Type II (B) is cytotoxic. Type IV (D) is delayed, T-cell mediated. No original E. This delayed onset, common with prolonged drug exposure, requires discontinuation and sometimes steroids, highlighting immune complex pharmacology in adverse reactions.
Question 2 of 5
A 79-year-old man with end-stage Alzheimer's disease and dysphagia is taking multiple medications. Physical examination reveals xerostomia and a limited gag reflex. Which of the following routes of medication administration would provide the lowest serum drug concentration?
Correct Answer: A
Rationale: Enteral (A) administration would provide the lowest serum drug concentration in this patient due to the challenges posed by his dysphagia and limited gag reflex, which impair swallowing and gastrointestinal absorption. Enteral routes (e.g., oral) rely on GI uptake, which can be erratic or reduced in such conditions, further complicated by xerostomia reducing dissolution. Intramuscular (B) and intravenous (D) routes deliver drugs directly into systemic circulation, yielding higher concentrations. Intrathecal (C) targets the CSF, not serum, but still achieves systemic levels. Transdermal (original E) offers steady absorption but higher serum levels than enteral in this context. Given his swallowing difficulties, enteral drugs face significant barriers (e.g., incomplete absorption, first-pass metabolism), making it the least effective for systemic delivery, critical in managing polypharmacy in Alzheimer's patients.
Question 3 of 5
A 27-year-old man with HIV disease and hepatic insufficiency presents to his primary care physician complaining of rectal pain and bleeding with bowel movements. Physical examination reveals several internal and external hemorrhoids. The patient would like to avoid surgical therapy for this condition. Which of the following routes of drug administration would be preferred in this patient?
Correct Answer: D
Rationale: Rectal (D) administration is preferred for this patient with hemorrhoids, hepatic insufficiency, and HIV, delivering drugs (e.g., hydrocortisone suppositories) directly to the site, minimizing systemic exposure and hepatic metabolism. Enteral (A) risks first-pass metabolism, worsened by liver dysfunction. Intramuscular (B) and intravenous (C) are systemic, unnecessary for local relief. Transdermal (original E) is impractical for rectal tissue. Rectal's local action reduces systemic load, critical in hepatic compromise, offering rapid relief, patient comfort, and avoiding surgical risks in an immunocompromised state.
Question 4 of 5
The therapeutic index of a drug is the ratio of the dose that produces toxicity to the dose that produces an efficacious response. By this definition, which of the following medications has the largest therapeutic index?
Correct Answer: A
Rationale: Diazepam (A) has the largest therapeutic index (TI = TD50/ED50), often >100, as its toxic dose (e.g., respiratory depression) far exceeds its anxiolytic dose, making it relatively safe. Digoxin (B), gentamicin (C), lithium (D), and theophylline (original E) have narrow TIs (<10), with toxicity (e.g., arrhythmias, ototoxicity, tremors, bronchospasm) near therapeutic doses. Diazepam's wide TI reflects its forgiving dose-response, critical in anxiolytics vs. drugs requiring tight monitoring, a key safety metric in pharmacology.
Question 5 of 5
A 22-year-old woman who is afraid of running into her former boyfriend actually meets him unexpectedly in a shopping mall. Her fears are because their former relationship was marked by physical and mental abuse. Memories of him are met with increased anxiety and fear. Which of the following physiologic responses would this woman be expected to exhibit at this time of seeing this man?
Correct Answer: C
Rationale: Hypertension (C) is expected due to sympathetic activation from fear and anxiety, releasing catecholamines (e.g., epinephrine), increasing heart rate and vasoconstriction. Bradycardia (A) opposes this fight-or-flight response. Diarrhea (B) may occur later but isn't immediate. Sweating (D) accompanies but is secondary. Tracheal deviation (original E) is unrelated. This acute stress response, mediated by the HPA axis and sympathetics, elevates BP, a physiologic adaptation to perceived threat, relevant in anxiety pharmacology.