pharmacodynamics

Question 1

What is pharmacodynamics?

Answer 1

What does the drug do with the body?

Question 2

Name the 2 types of receptors and explain them

Answer 2

1. agonist (It binds to the receptor and changes the receptor) e.g. ion channel opening
2. antagonist (they do bind to the recpetor, but no effect is measured). It does not change it’s conformation of the receptor.

Question 3

What does antagonists do?

Answer 3

They take the place for agonists. They do not create an effect themselves.

Question 4

Name the 2 types of ion chanels and explain them

Answer 4

1. blockers (they will enter the channel and block it, the permeation of ions is reduced)
2. modulators (they bind to the subunits of the ion channels usbunits and this will increase or decrease opening probability)

Question 5

Name the 3 different types of enzymes and explain

Answer 5

1. inhibitor (the normal reaction is inhibited)
2. a false substrate (abnormal metabolite produced, so the normal reaction will also be inhibited )
3. pro-dug (an active drug is produced)

Question 6

Name the 3 different types of transporters

Answer 6

1. normal transport (carries a substrate from one side of a barrier to the other side)
2. inhibitor (transport is blocked)
3. false substrate (a false substrate is carried across the barrier and blocks the normal substrate from passing)

Question 7

what is a drug?

Answer 7

A drug is an exogenous chemica; compound that modifies the functioning of a physiological system in a selective manner

Question 8

Drugs can bind with ………..

Answer 8

• receptors
• enzymes
• transporters
• ion channels

Question 9

What is affinity?

Answer 9

affinity is the tendency to bind to receptors (occupation)

Question 10

what is efficacy?

Answer 10

Efficacy is the relationship between receptor occupancy and the ability to initiate a response at the molecular, cellular, tissue or system level (activation)

Question 11

What is intrinsic activity?

Answer 11

Intrinsic activity is the capacity of a single drug receptor complex to evoke a response

Question 12

What is the occupancy postulate?

Answer 12

the agonist efficacy is proportionate to the occupancy grade of its receptor at increasing drug concentrations

Question 13

What does the kd stand for?

Answer 13

Kdissociation is the affinity of the binding of the agonist to the receptor

Question 14

What is the EC50?

Answer 14

the dose at which the half-maximal effect of a particular drug is achieved

Question 15

the EC50 represents the Kd or a measure of affinity

Answer 15

okay

Question 16

What is the potency?

Answer 16

When a drug has a higher potency, it evokes a repsonse at lower concentrations

Question 17

What is the difference between efficacy, potency and ec50?

Answer 17

The efficacy and ec50 are the same thing. The potency is the relationship between the drug concentration and a response.

Question 18

describe the lock and key model

Answer 18

the idea that certain drugs fit like a key into a lock (the receptor)

Question 19

What happens when a competitive antagonist (inhibitor) is added to a receptor?

Answer 19

then more concentration of the agoinst is needed to reach the same effect

Question 20

What is a non-competitive antagonist?