Basic Pharmocology principles II

Question 1

Does more drug mean more effect?

Answer 1

not always no

Question 2

What is potency?

Answer 2

The relative measures of a chemicals effectiveness

• the more potent the chemical, the less it takes to exert its force
• Dose-response curves illustrate the relative potency of various drugs

Question 3

Does drugs potency typically matter

Answer 3

typically no; unless the more potent drug….

• is capable of producing a greater maximal response than a lower potency drug
• the more potent drugs induces a lower incidence of side effects
• the more potent drugs induces the benefits more quickly

Question 4

Dose-Response Curves are Only One Factor Used

to Determine Therapeutic Index…..

Answer 4

• Drug Half-Life
• ED50 – Median Effective Dose
• LD50 – Median Lethal Dose
• TD50 – Median Toxic Dose
• Therapeutic index is the ratio of LD50 to ED50

Question 5

What is affinity

Answer 5

the ability of a ligand to maintain contact with the receptor module

Question 6

What is intrinsic activity

Answer 6

Efficiency: the relative activation effect of a ligand on the receptor and ultimately the cell

Question 7

what is an agonist

Answer 7

a ligand that has both an affinity for and an activation effect on receptors

Question 8

Whats the difference between a full and partial agonist

Answer 8

A full agonist produces the maximal (100%) response

a partial agonist is a drug that has lower than the maximal response of an agonist

Question 9

whats an indirect agonist

Answer 9

a chemical that does not bind with a receptor but otherwise enhances the actions of the ligand

Question 10

what is an inverse agonist

Answer 10

activates the same receptor as a ligand but has the opposite effect

Question 11

what is a mixed agonist/antagonist

Answer 11

when a drug BOTH:

• has the same or similar effect as another drug or group of drugs and
• to some effect, counteracts that

Question 12

what is an antagonist?

Answer 12

a drug that blocks that action of another molecule or ligand (has affinity but not efficiency)

Question 13

What is a competitive antagonist?

Answer 13

does not produce any pharmacological effect but decreases the effectiveness of an antagonist by competing for receptors

Question 14

What is a non-competitive agonist?

Answer 14

does not produce any pharmacological effect but decreases the maximal response by eliminating receptors

Question 15

What is a pharmacologic antagonism?

Answer 15

• occurs when a drug has the ability to bind to a receptor, but has no activation effect (high affinity but low efficiency)
• ultimate effect is that the potency of the agonist is reduced

Question 16

What is a physiologic antagonism?

Answer 16

• drug interaction
• occurs when two drugs acting at different receptors produce opposing effects
• both drugs antagonize eachother
• drugs may be either agonists or antagonists

Question 17

Drug Interactions: Additivity & Synergism/Potentiation occur when…..

Answer 17

2 drugs are given concurrently that have the same biological effect (ie drowsiness)

Question 18

descibe the additivity and synergism/potentiation patterns

Answer 18

additivity: the effects summate

synergism/potentiation: one drug enhances the others effect such that the combined effect exceeds additivity predication