Pharmacology of Anesthetic Agents Flashcards

Which opioid has the highest lipid solubility and fastest onset among commonly used IV opioids?

Answer: Fentanyl

Fentanyl's high lipid solubility enables rapid CNS penetration and onset within 1-2 minutes.

Ketamine's analgesic mechanism is primarily attributed to antagonism of which receptor?

Answer: NMDA receptor

Ketamine blocks NMDA receptors, producing dissociative anesthesia and profound analgesia.

Which volatile anesthetic has the lowest blood-gas partition coefficient, resulting in the fastest emergence?

Answer: Desflurane

Desflurane has a blood-gas partition coefficient of 0.42, the lowest among modern volatile agents, enabling the fastest emergence.

What is the primary mechanism by which succinylcholine causes prolonged neuromuscular blockade in patients with pseudocholinesterase deficiency?

Answer: Inability to hydrolyze the drug in plasma

Pseudocholinesterase normally hydrolyzes succinylcholine in plasma; deficiency prevents this breakdown, prolonging blockade.

Dexmedetomidine produces sedation primarily through agonism at which receptor subtype?

Answer: Alpha-2 adrenergic

Dexmedetomidine is a selective alpha-2 adrenergic agonist that produces sedation via locus coeruleus pathways.

Which benzodiazepine reversal agent is used to treat midazolam-induced respiratory depression?

Answer: Flumazenil

Flumazenil is a competitive GABA-A antagonist that reverses benzodiazepine-induced sedation and respiratory depression.

The context-sensitive half-time of remifentanil is unique because it:

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.