Pharmacology: Intro

Question 1

pharmacodynamics

Answer 1

• biological effect and MoA

- what a drug does to the body

Question 2

pharmacokinetics

Answer 2

• absorption, distribution, metabolism, excretion

- what the body does to a drug

Question 3

what is drug selectivity

Answer 3

ability of a drug to distinguish between different receptors in the body

Question 4

how do drugs act

Answer 4

by binding to and modifying regulatory proteins

Question 5

agonist

Answer 5

binds to a target and induces its cellular response

Question 6

antagonist

Answer 6

binds to a target and reduces or blocks an agonists actions

Question 7

how does an agonist work

Answer 7

binds reversibly activating receptor and inducing a reversible conformational change

Question 8

write the equilibrium equation showing the un/binding and de/activation of an agonist
what step shows affinity and what one shows efficacy

Answer 8

A+R -K+1-> AR -beta-> AR*

A+R

Question 9

affinity

Answer 9

strength of association

Question 10

what is the disscoiation rate if an agonist has
- high affinity
- low affinity
and what does the equilibrium favour

Answer 10

• slow dissociation rate (AR - K+1))

- fast dissociation rate (R - K-1)

Question 11

what is affinity determined by

Answer 11

chemicak bonds between receptor and its ligand

Question 12

efficacy

Answer 12

agonists ability to envoke a cellular response

Question 13

what is the response if an agonist has
- high efficacy
- low efficacy
and what does the equilibrium favour

Answer 13

• large response (AR* - Beta)

- small response (AR - alpha)

Question 14

what is a drugs selectivity dependent on

Answer 14

dose and route of administration

Question 15

what happends with selectivity if a dose given is too high

Answer 15

the drug acts off target and selectivity is lost, producing unwanted adverse effects

Question 16

how does an antagonist work

Answer 16

binds, usually reversibly, and blocks the effects of an agonist - no activation

Question 17

write the equilibrium equation showing the binding of an antagonist

Answer 17

B+R -K+1-> BR

B+R

Question 18

what happens to the no of agonist receptors if the agonist concentration increases
- what shape does this take on a graph

Answer 18

• as agonist conc. increases, no of receptors increases correspondingly
• hyperbolic

Question 19

what happens to the response if the dose of a drug increases
- what shape does this take on a linear graph

Answer 19

an increase in dose will increase the response

- hyperbolic

Question 20

EC50

Answer 20

dose required to produce a half maximal response

Question 21

why would you plot a drug dose and response graph on semi-logarithmic paper
what shape would it take

Answer 21

• allows you to plot more agonist concentrations and gives a more accurate reading of EC500
• sigmoidal

Question 22

potency

Answer 22

the amount of drug needed to produce a certain level of response

Question 23

agonist response curve

- describe the relationships of agonists, potency and efficacy comparing drug A, B and C

Answer 23

**

Question 24

describe competitive antagonism and how its overcome

Answer 24

• agonist and antagonist bind to same orthosteric site

- increasing agonist conc.

Question 25

describe non-competitive antagonism

Answer 25

• agonist binds at orthosteric site but antagonist binds at different allosteric site
• both can occupy the receptors at the same time but no receptor activation will occur

Question 26

what happens to the agonist response curve with competitive agonism

Answer 26

• R shift

- max response unchanged (need greater agonist conc.)

Question 27

what happens to the agonist response curve with non-competitive agonism

Answer 27

• no shift

- max response depressed (agonist conc. has no effect)