ATI RN
Chapter 26 principles of pharmacology Questions
Question 1 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 2 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.
Question 3 of 5
Researchers interested in studying a certain cytochrome P450 enzyme wish to isolate the enzyme of interest from the many other proteins in the cells. One of their initial steps is to lyse the cells and isolate the organelle which carries the enzyme they want to study. Which organelle will they isolate to find CYP enzymes?
Correct Answer: E
Rationale: Smooth endoplasmic reticulum (E, original) houses CYP enzymes, where phase I metabolism (e.g., oxidation) occurs in hepatocytes. Golgi (A) processes proteins, lysosomes (B) degrade waste, mitochondria (C) produce energy, and peroxisomes (D) handle fatty acids. SER's microsomal fraction, rich in CYPs (e.g., CYP3A4), is isolated via centrifugation, critical for studying drug metabolism, enzyme induction (e.g., by rifampin), and interactions, a foundational step in pharmacology research.
Question 4 of 5
A 24-year-old woman presents to her primary care physician complaining of feeling sleepy all the time. She has a history of hay fever since the age of 9 years. She is currently taking an antihistamine but cannot remember the name. She says it controls her hay fever symptoms well. You suspect that her medication is causing her to feel sleepy. First generation antihistamines can cause drowsiness because they cross the blood-brain barrier and act on which receptor?
Correct Answer: A
Rationale: First-generation antihistamines (e.g., diphenhydramine) cause drowsiness by crossing the BBB and blocking H₠receptors (A) in the CNS, reducing alertness. H₂ (B) regulates gastric acid. H₃ (C) modulates histamine release. H₄ (D) affects immunity. Their lipid solubility enables CNS penetration, unlike second-generation (e.g., cetirizine), critical in hay fever management, where sedation is a trade-off for symptom relief, guiding drug choice.
Question 5 of 5
A medical student is involved in a summer research project evaluating the excitatory and inhibitory effects of five neurotransmitters. Following as choices are the five neurotransmitters and their excitatory and inhibitory status. Which of the following neurotransmitters is likely to be serotonin?
Correct Answer: C
Rationale: Failed to generate a rationale of 500+ characters after 5 retries.