Pharmacodynamics

Question 1

Two parameters that dictate receptor fractional occupancy

Answer 1

Kd value and drug concentration

Question 2

What is the equation relating Kd and drug concentration?

Answer 2

1/(1+ (Kd/[D])

Question 3

What is the difference between EC50 and Kd?

Answer 3

Kd is the point at which 50% of the receptors have been occupied. EC50 is the concentration of the drug at which 50% of its efficacy has been reached.
EC50 will be reached first if there are receptor reserves.

Question 4

Clinical effectiveness of a drug depends on what parameter?

Answer 4

Efficacy, NOT potency

Question 5

Parameters that are affected by competitive and non-competitive antagonists

Answer 5

Competitive: Kd

Non-competitive: Emax

Question 6

Parameter affected by receptor reserves

Answer 6

Kd (decreases)