Pharmacodynamics Flashcards Preview

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Flashcards in Pharmacodynamics Deck (21):
1

Receptor

Binds drugs, transduces binding into a response

2

Ligands

Drugs, bind to receptors

3

KD

KD = k2/k1 = [L] * [R]/[LR]

  • Equilibrium, dissociation constant
  • Describes the goodness of fit between ligand and receptor
  • Inversely related to the affinity of ligand for the receptor
  • Has units of concentration

4

Affinity

The ability of the drug to bind to a receptor

5

RT

RT = [LR] + [R]

Total number of receptors in a cell or tissue (bound and unbound)

6

Intrinsic activity

(α), measure of the ability of the LR complex to elicit the effect being measured, also called efficacy

  • Is the ratio of the Emax of the ligand of interest to the Emax of a full agonist
  • Full agonist, α = 1
  • Antagonist, α = 0

7

Agonist

Drug with an intrinsic activity (α) of 1

8

Antagonist

Drug with an intrinsic activity (α) of 0

9

Partial agonist

Drug with an intrinsic activity (α) between 0 and 1

10

Spare receptors

Increase the sensitivity of the cell to a low concentration of ligand

Allows for high sensitivity without long activation time

11

Potency

The relationship between the amount of drug administered and its effect, determines the position of the curve on the x-axis

Determined by:

  • Affinity for the site of action
  • Ability to reach site of action

 

12

Efficacy

Intrinsic activity, the relative ability of a drug-receptor complex to produce a maximum functional response

Determined by:

  • Intrinsic activity
  • Characteristics of the effector
  • Limitations on the amount of drug that can be administered

13

Maximum efficacy

Maximal effect that is produced by a drug, it is the maximum point on the y-axis that is reached

14

ED50

the dose that produces the desired effect in half of the population

15

Hypersensitivity

allergic or inflammatory response to a drug

16

Hyperreactive

an unusually low dose of drug produces its expected pharmacologic effects

17

Hyporeactive

require exceptionally large doses of drug to evoke expected pharmacologic effects

18

Therapeutic index

Ratio of TD50/ED50

The ratio of the dose that produces a toxic effect in half of the population to the dose that produces the desired effect in half of the population

19

TD50

Median toxic dose

the dose that produces a toxic effect in half of the population

20

LD50

Median lethal dose

the dose that kills in half of the population

21

Log-normal distribution

You know what it is.