foundation pharm

Question 1

what are the 3 types of antagonists

Answer 1

• competitive antagonist - bind to same binding site as endogenous ligand and compete for the same R
• non-competitive not at receptor - bind to allosteric R –> stops stimulus
• non competitive at receptor - activation of R with opposite effect

Question 2

the effect of an antagonist depends on:

Answer 2

• the efficacy of the agonist

- the affinity of the antagonist

Question 3

how does binding to the allosteric site affect the R

Answer 3

• modulation of orthosteric ligand affinity
• modulation of orthosteric ligand efficacy
• modulation of R activation level

Question 4

what are the advantages of using drugs that bind to the allosteric site

Answer 4

• substantial selectivity between R subtypes

- incomplete antagonism possible

Question 5

what is surmountable antagonism

Answer 5

antagonism that is able to be overcome

- you can get the response back by increasing the conc of the agonist

Question 6

what kind of receptor is the beta-adrenoceptor

Answer 6

GPCR

Question 7

what are the 4 types of receptors

Answer 7

GPCR
ligand gated ion channels
kinase-linked
nuclear

Question 8

what are the subtypes of nicotinic receptors

Answer 8

NM - muscular

NN - autonomic ganglia

Question 9

what is the difference between pharmacokinetics and pharmacodynamics

Answer 9

PK - what the body does to the drug

PD - what the drug does to the body

Question 10

what is the therapeutic windown

Answer 10

the dose between starting to have an effect and toxicity

Question 11

what is the difference between a full and partial agonist

Answer 11

full - gives maximal effect of activating the R

partial - gives only partial effect of activating the R

Question 12

what is potency

Answer 12

the smallest amount you can give for an effect

Question 13

how is potency measured

Answer 13

usually measured by EC50 = half of max

Question 14

what is efficacy

Answer 14

the strength of the R activation

Question 15

what are the parts of pharmacokinetics

Answer 15

administration, absorption
distribution
elimination (metabolism, excretion)
(AADME)

Question 16

most drugs are eliminated at a rate …

Answer 16

proportional to the conc in the plasma

when conc falls, so does the rate of elimination

Question 17

what factors will affect drug distribution

Answer 17

• molecular size –> small enough to cross vascular endothelium
• ability to bind plasma proteins - unable to get out of vessels
• lipid solubility - go through the cell membrane

Question 18

which types of drugs can pass through the BBB

Answer 18

lipid soluble

Question 19

drug reservoirs can lead to…

Answer 19

• prolonging drug action
• can quickly terminate action
• can led to slow distribution

Question 20

what are 3 drug reservoirs

Answer 20

plasma protein
cells
fat

Question 21

what is the volume of distribution

Answer 21

the volume of body water in which a drug appears to be dissolved in after it has distributed throughout the body

Question 22

what is the equation for volume of distribution

Answer 22

amount in body / conc in plasma

Question 23

what factors influence the volume of distribution

Answer 23

• if drug binds to plasma protein –> greater conc appears in plasma –> VD is small
• if drug binds to tissues/taken up by cells –> drug stripped from the plasma –> VD is large

Question 24

what is the point of working out the volume of distribution

Answer 24

tells you the dose that you must give to a patient IV to get a desired plasma conc

Question 25

drugs are eliminated via

Answer 25

excretion (kidney)

metabolism (liver)

Question 26

which type of drug will not be filtered in the glomerulus

Answer 26

drugs that are bound to plasma proteins

Question 27

what is the association between lipid solubility and pH

Answer 27

lower pH - acidic drugs are more lipid soluble and basic drugs are not lipid soluble

Question 28

formula for renal clearance

Answer 28

GFR + TS - TR

Question 29

maximal drug clearance is what

Answer 29

800ml/min