Pharmacodynamics

Question 1

Maximal efficacy Emax

Answer 1

Largest effect that a drug can produce

Question 2

ED50

Answer 2

Does of drug that is required to provide the therapeutic effect in 50% of test population

Question 3

LD50

Answer 3

Does of drug that is lethal in 50% of tested animals.

• can also be the does that produces adverse drug effects in 50% of the test populations

Question 4

Therapeutic index (T.I.)

Answer 4

Ratio of LD/ED

Question 5

High T.I.

Answer 5

Drug is not easy to OD on

Question 6

Low T.I.

Answer 6

Drug is very easy to OD on

Question 7

Efficacy comparison

Answer 7

Increase or decreases in maximal efficacy (effectiveness) of two or more drugs

• increases efficacy = greater Emax within the same ED50

Question 8

Potency comparison

Answer 8

Increases or decreases in ED dose between two or more drugs

• greater potency = lower ED50 with the same Emax

Question 9

Ligand

Answer 9

Agonist or antagonist chemical that binds to a receptor

Question 10

Affinity

Answer 10

Measured attraction of a drug to its receptor

Question 11

Selectivity

Answer 11

Specific affinity for certain receptors vs other receptors

MDMA receptor would have higher affinity for MDMA vs a M2 receptor

Question 12

Competitive antagonists

Answer 12

Reduce potency of agonists, but no not affect efficacy

Increase dose needed to hit ED50

Question 13

Non competitive antagonists

Answer 13

Reduce efficacy (Emax)

Question 14

Physiological antagonists

Answer 14

Activate independent physiological responses that oppose agonist-mediated physiological responses

Question 15

Transcription factor receptor

Answer 15

Intracellular receptor that activates or inhibits gene transcription.

• increases/decreases biological responses

Question 16

G-protien coupled receptor

Answer 16

Activated receptor uses G-protein 2nd messenger systems to create biological responses.

Question 17

Sensitivity

Answer 17

Up-regulation of receptors via antagonist presence.

• removing antagonist allows greater agonist effects

Question 18

Tolerance

Answer 18

Down regulation of receptors due to long term agonist exposure

Question 19

Partial agonists

Answer 19

Function similarly to full agonist but have a lower Emax

Question 20

Additive interaction

Answer 20

The effectiveness of 2 drugs combined is equal to the sum of individual effects

Question 21

Synergistic

Answer 21

The effectiveness of two drugs is greater than the individual effectiveness of each drug.

Question 22

Tachyphylaxis

Answer 22

Decreased drug response often by initial/repeated administration of a drug (similar to tolerance)