EDAIC Pharmacokinetics and Pharmacodynamics 3

Question 1

Which statement about the Hill equation (sigmoid Emax model) is correct?

Accepted Answer

A higher γ produces a steeper sigmoid curve with a narrower dynamic range

Answer

A larger Hill coefficient (γ) steepens the sigmoid curve, meaning a narrow concentration range spans from minimal to maximal effect.

Question 2

A drug with a narrow therapeutic index and primarily renal elimination is most dangerous in which clinical scenario?

Accepted Answer

Acute kidney injury with oliguria

Answer

Acute kidney injury reduces renal drug clearance, causing drug accumulation and toxicity for renally eliminated narrow therapeutic index drugs.

Question 3

The concept of 'pharmacodynamic tolerance' is best illustrated by which scenario?

Accepted Answer

Opioid dose escalation required over time to achieve the same analgesic effect

Answer

Pharmacodynamic tolerance refers to reduced drug effect at the same concentration over time, classically seen with opioid analgesia due to receptor downregulation or desensitization.

Question 4

Which best explains why acidosis increases the free fraction of a weakly acidic, highly protein-bound drug?

Accepted Answer

Competition between H+ ions and the drug for albumin binding sites displaces the drug

Answer

In acidosis, H+ ions compete with weakly acidic drugs for albumin binding sites, displacing the drug and increasing its free (unbound) fraction.

Question 5

When two drugs produce synergistic anesthesia, their combined isobologram shows the interaction point:

Accepted Answer

Below the line of additivity

Answer

Synergism means less of each drug is needed together than expected from pure additivity, so the interaction point falls below the additive isobole line.

EDAIC - European Diploma in Anesthesiology and Intensive Care Practice Test

EDAIC - European Diploma in Anesthesiology and Intensive Care Practice Test

EDAIC Pharmacokinetics and Pharmacodynamics 3