BCA Pharmacology of Anesthetic Agents 2 — Questions and Answers
Question 1: Which opioid has the highest lipid solubility and fastest onset among commonly used IV opioids?
- Morphine
- Hydromorphone
- Fentanyl (Correct answer)
- Meperidine
Correct answer: Fentanyl
Fentanyl's high lipid solubility enables rapid CNS penetration and onset within 1-2 minutes.
Question 2: Ketamine's analgesic mechanism is primarily attributed to antagonism of which receptor?
- Mu-opioid receptor
- GABA-A receptor
- NMDA receptor (Correct answer)
- Alpha-2 adrenergic receptor
Correct answer: NMDA receptor
Ketamine blocks NMDA receptors, producing dissociative anesthesia and profound analgesia.
Question 3: Which volatile anesthetic has the lowest blood-gas partition coefficient, resulting in the fastest emergence?
- Isoflurane
- Sevoflurane
- Desflurane (Correct answer)
- Halothane
Correct answer: Desflurane
Desflurane has a blood-gas partition coefficient of 0.42, the lowest among modern volatile agents, enabling the fastest emergence.
Question 4: What is the primary mechanism by which succinylcholine causes prolonged neuromuscular blockade in patients with pseudocholinesterase deficiency?
- Increased receptor sensitivity
- Impaired hepatic metabolism
- Inability to hydrolyze the drug in plasma (Correct answer)
- Accumulation of active metabolites
Correct answer: Inability to hydrolyze the drug in plasma
Pseudocholinesterase normally hydrolyzes succinylcholine in plasma; deficiency prevents this breakdown, prolonging blockade.
Question 5: Dexmedetomidine produces sedation primarily through agonism at which receptor subtype?
- Alpha-1 adrenergic
- Alpha-2 adrenergic (Correct answer)
- Beta-1 adrenergic
- Dopamine D2
Correct answer: Alpha-2 adrenergic
Dexmedetomidine is a selective alpha-2 adrenergic agonist that produces sedation via locus coeruleus pathways.
Question 6: Which benzodiazepine reversal agent is used to treat midazolam-induced respiratory depression?
- Naloxone
- Sugammadex
- Flumazenil (Correct answer)
- Neostigmine
Correct answer: Flumazenil
Flumazenil is a competitive GABA-A antagonist that reverses benzodiazepine-induced sedation and respiratory depression.
Question 7: The context-sensitive half-time of remifentanil is unique because it:
- Increases dramatically with infusion duration
- Remains constant regardless of infusion duration (Correct answer)
- Decreases with longer infusions
- Doubles every 30 minutes of infusion
Correct answer: Remains constant regardless of infusion duration
Remifentanil is metabolized by nonspecific plasma esterases, keeping its context-sensitive half-time at ~3-4 minutes regardless of infusion duration.
BCA Pharmacology of Anesthetic Agents 2
Which opioid has the highest lipid solubility and fastest onset among commonly used IV opioids?