FFICM Pharmacology Fundamentals 2

Question 1

Which pharmacokinetic parameter describes the time for plasma concentration to fall by 50% after distribution equilibrium?

Accepted Answer

Context-sensitive half-time

Answer

Context-sensitive half-time reflects the time for plasma concentration to halve after stopping an infusion, and varies with infusion duration unlike a simple elimination half-life.

Question 2

A patient on phenytoin requires an increased dose of vecuronium. The most likely pharmacokinetic explanation is:

Accepted Answer

Induction of hepatic CYP450 enzymes increasing vecuronium metabolism

Answer

Phenytoin is a potent CYP450 inducer that accelerates hepatic metabolism of vecuronium, reducing its plasma concentration and duration of action.

Question 3

Which statement best describes zero-order kinetics?

Accepted Answer

A constant amount of drug is eliminated per unit time regardless of concentration

Answer

Zero-order kinetics occurs when elimination pathways are saturated, so a fixed amount (not fraction) of drug is cleared per unit time.

Question 4

The loading dose of a drug is primarily determined by:

Accepted Answer

Volume of distribution and target plasma concentration

Answer

Loading dose = (Volume of distribution × Target plasma concentration) / Bioavailability, making Vd the dominant determinant.

Question 5

Which receptor type mediates the inotropic effects of dopamine at doses of 5–10 mcg/kg/min?

Accepted Answer

Beta-1 adrenoceptors

Answer

At intermediate doses (5–10 mcg/kg/min), dopamine predominantly stimulates beta-1 adrenoceptors, increasing heart rate and contractility.

(FFICM) Final Faculty of Intensive Care Medicine Practice Test

(FFICM) Final Faculty of Intensive Care Medicine Practice Test

FFICM Pharmacology Fundamentals 2