FANZCA FANZCA Clinical Pharmacology and Anesthesia 2

Question 1

Which pharmacodynamic parameter describes the concentration of a drug required to produce 50% of its maximum effect?

Accepted Answer

EC50

Answer

The EC50 (effective concentration 50%) represents the drug concentration at which 50% of the maximum pharmacological effect is achieved, reflecting potency.

Question 2

What is the primary mechanism by which ketamine produces dissociative anesthesia?

Accepted Answer

NMDA receptor antagonism

Answer

Ketamine primarily acts as an NMDA receptor antagonist, blocking glutamate-mediated excitation to produce its characteristic dissociative state, analgesia, and bronchodilation.

Question 3

Which inhalational agent is contraindicated in patients with a known or suspected genetic predisposition to malignant hyperthermia?

Accepted Answer

All potent volatile halogenated agents

Answer

All potent volatile halogenated agents (halothane, isoflurane, sevoflurane, desflurane) are triggers for malignant hyperthermia and must be avoided in susceptible patients.

Question 4

What is the clinical significance of the context-sensitive half-time in intravenous anesthetic pharmacokinetics?

Accepted Answer

It represents the half-life of a drug after infusion ceases, which increases with longer infusions for many drugs

Answer

Context-sensitive half-time is the time for plasma concentration to fall by 50% after stopping an infusion; for drugs like fentanyl, this lengthens considerably with prolonged infusions.

Question 5

Which drug class used in anesthesia acts by inhibiting cyclooxygenase enzymes to provide multimodal analgesia as part of an opioid-sparing strategy?

Accepted Answer

NSAIDs

Answer

NSAIDs reduce prostaglandin synthesis by inhibiting COX-1 and COX-2 enzymes, providing anti-inflammatory analgesia that reduces opioid requirements perioperatively.

(FANZCA) Fellowship of the Australian and New Zealand College of Anaesthetists Practice Test

(FANZCA) Fellowship of the Australian and New Zealand College of Anaesthetists Practice Test

FANZCA FANZCA Clinical Pharmacology and Anesthesia 2