CSC Pharmacology of Sedative Agents 2 — Questions and Answers
Question 1: Which benzodiazepine is most commonly used for conscious sedation due to its rapid onset and amnestic properties?
- Diazepam
- Midazolam (Correct answer)
- Lorazepam
- Clonazepam
Correct answer: Midazolam
Midazolam is preferred for conscious sedation because of its rapid onset (2–3 min IV), short duration, and reliable anterograde amnesia.
Question 2: What is the primary mechanism by which propofol produces sedation?
- NMDA receptor antagonism
- Opioid receptor agonism
- GABA-A receptor potentiation (Correct answer)
- Alpha-2 adrenergic agonism
Correct answer: GABA-A receptor potentiation
Propofol enhances GABA-A receptor-mediated chloride influx, producing CNS depression and sedation.
Question 3: A patient receives fentanyl for procedural sedation. Which effect is MOST likely to require intervention?
- Bradycardia
- Respiratory depression (Correct answer)
- Hypertension
- Hyperglycemia
Correct answer: Respiratory depression
Fentanyl, like all opioids, can cause dose-dependent respiratory depression, which is the primary life-threatening risk.
Question 4: Which drug is the reversal agent for benzodiazepine-induced sedation?
- Naloxone
- Neostigmine
- Flumazenil (Correct answer)
- Sugammadex
Correct answer: Flumazenil
Flumazenil competitively antagonizes benzodiazepine binding at the GABA-A receptor, reversing sedation and respiratory depression.
Question 5: Ketamine produces dissociative sedation primarily through which receptor mechanism?
- GABA-A potentiation
- NMDA receptor antagonism (Correct answer)
- Mu-opioid agonism
- Beta-adrenergic blockade
Correct answer: NMDA receptor antagonism
Ketamine blocks NMDA (N-methyl-D-aspartate) glutamate receptors, producing its unique dissociative anesthetic state.
Question 6: Which of the following is a unique advantage of dexmedetomidine compared to other sedatives used in procedural sedation?
- It provides complete amnesia
- Patients remain easily arousable and cooperative (Correct answer)
- It has a reversal agent
- It eliminates the need for airway monitoring
Correct answer: Patients remain easily arousable and cooperative
Dexmedetomidine produces sedation without significant respiratory depression, and patients remain arousable and able to follow commands.
Question 7: What is the half-life of flumazenil and why is this clinically significant?
- 30–60 minutes; re-sedation can occur after reversal (Correct answer)
- 4–6 hours; it outlasts most benzodiazepines
- 10–15 minutes; must be given every 10 minutes indefinitely
- 2–4 hours; it causes prolonged wakefulness
Correct answer: 30–60 minutes; re-sedation can occur after reversal
Flumazenil's half-life of approximately 30–60 minutes is shorter than most benzodiazepines, meaning re-sedation may occur and the patient must be monitored.
CSC Pharmacology of Sedative Agents 2
Which benzodiazepine is most commonly used for conscious sedation due to its rapid onset and amnestic properties?