B2.i · Receptor Theory

Official V5 objective

With respect to receptor theory, explain the concepts of drug action, including the following: a. law of mass action b. affinity c. association and dissociation constants

1 SAQ topic 1 SAQ appearance 1 VIVA station

Written examination

SAQ history

1 appearance

Drug–Receptor Affinity

1 exam appearance

2007B Q12

The binding of a drug (D) to its receptor (R) is described by the equation D + R -> DR. Explain the following: a) The ratio of koff / kon b) The implications for a low value for the ratio c) The term affinitiy d) The clinical implications for a high value for affinitiy e) Two physiological factors that affect the rate constant

14%

Oral examination

VIVA history

1 station

2016A · Day 2 · VIVA 8
This was a general pharmacology viva about drug receptor interactions, receptor classification and concepts of affinity and rate constants. The viva explored knowledge of dose response curves and the concepts of potency and efficacy. The viva went on discuss plasma concentration curves, exponential functions and drug kinetics and compartment distributions.

Pass rate not reported

Sources: objective text from the relevant CICM syllabus; historical SAQ and VIVA wording from CICM examiner reports.