EDAIC Pharmacokinetics and Pharmacodynamics 5

Question 1

The minimum alveolar concentration (MAC) of a volatile anesthetic is best described as the concentration that:

Accepted Answer

Prevents movement in 50% of patients in response to a surgical skin incision

Answer

MAC is defined as the alveolar concentration of volatile anesthetic at 1 atm that prevents purposeful movement in response to a surgical skin incision in 50% of patients.

Question 2

Drug protein binding primarily affects pharmacokinetics by influencing:

Accepted Answer

The free (unbound) fraction available for distribution, metabolism, and effect

Answer

Only the free (unbound) fraction of a drug can cross membranes, interact with receptors, undergo metabolism, and be filtered by the glomerulus.

Question 3

A pharmacokinetic-pharmacodynamic (PK-PD) model incorporating an 'effect compartment' (Ce) is necessary because:

Accepted Answer

There is a time lag between plasma concentration and pharmacological effect

Answer

The effect compartment model accounts for hysteresis (the clockwise delay loop) between plasma drug concentrations and observed pharmacological effects.

Question 4

Which statement about the oil:gas partition coefficient of volatile anesthetics is correct?

Accepted Answer

Higher oil:gas coefficient indicates greater lipid solubility and lower MAC

Answer

Higher oil:gas partition coefficient indicates greater lipid solubility and thus higher potency, corresponding with a lower MAC value (Meyer-Overton correlation).

Question 5

Morphine-6-glucuronide (M6G) is clinically significant because it:

Accepted Answer

Is a more potent mu-opioid agonist than morphine and accumulates in renal failure

Answer

M6G is an active metabolite with greater mu-opioid receptor affinity than morphine, and it accumulates to toxic levels in renal failure due to impaired renal excretion.

EDAIC - European Diploma in Anesthesiology and Intensive Care Practice Test

EDAIC - European Diploma in Anesthesiology and Intensive Care Practice Test

EDAIC Pharmacokinetics and Pharmacodynamics 5