Clinical Dose Response

Question 1

can be constructed for responses that are measured on a continuous scale, eg, heart rate.

Answer 1

graded dose-response curve

Question 2

relate the intensity of response to the size of the dose, and hence are useful for characterising the actions of drugs

Answer 2

graded dose-response curve

Question 3

can be constructed for drugs and elicit an all-or-non response, eg, presence or absence of epileptic seizures.

Answer 3

quantal dose-response curve

Question 4

The percentage of the population requiring a particular dose to exhibit the effect can be determined from this curve. When these data are plotted as a cumulative frequency distribution, a ____________ is generated.

Answer 4

sigmoidal dose-response curve

Question 5

for most drugs, the doses that are required to produce a specified quantal effect in a population are log normally distributed, so that the frequency distribution of responses plotted against log dose is a?

Answer 5

Gaussian normal distribution curve

Question 6

is the ratio of rate constants for the reverse

Answer 6

Kd

Question 7

reaction between the drug receptor and the drug-receptor complex

Answer 7

K1

Question 8

ratio of rate constants for the forward

Answer 8

K2

Question 9

also the drug concentration at which receptor occupancy is half of maximum.

Answer 9

Kd

Question 10

drugs with a high Kd dissociate rapidly from receptors

Answer 10

low affinity

Question 11

drugs with a low kd dissociate slowly from receptors

Answer 11

high affinity

Question 12

examples of specific drugs include?

Answer 12

✓ atropine
✓ salbutamol
✓ phenoxybenzamine
✓ cimetidine

Question 13

muscarinic antagonist

Answer 13

atropine

Question 14

a B2-adrenoceptor agonist

Answer 14

salbutamol

Question 15

an a-alergic blocking agent

Answer 15

phenoxybenzamine

Question 16

which causes blockade of D2-dopamine receptors, a-adregenic receptors and muscarinic receptors.

Answer 16

phenothiazine

Question 17

a drug is the ration of the dose that results in an undesired effect to that which results in a desired effect

Answer 17

therapeutic index

Question 18

the therapeutic index of a drug is usually define as the ratio of ____________ to ___________ which indicates how selective the drug is in resulting in its desired effect.

Answer 18

LD50 to ED50

Question 19

Values of Ld50 and Ed50 for this purpose are derived from ______________ generated in animal studies.

Answer 19

quantal dose-response curves

Question 20

the information obtained from __________ is critically important when choosing between drugs and when determining the dose to administer

Answer 20

dose-response curves

Question 21

primary determinants of a drug’s clinical effectiveness

Answer 21

efficacy of the drug-receptor complex

Question 22

is derived from a quantitative dose-response relationship for a single animal and varies among individuals

Answer 22

Emax

Question 23

provides information concerning the dose range over which a drug elicits its effect.

Answer 23

slope of the graded dose-response curve

Question 24

when quantal effects are being considered information concerning pharmacological potency, selectivity of a drug action, the margin of safety and the potential variability of responsiveness among individuals is obtained from?

Answer 24

quantal dose-response curves

Question 25

an indication of the ability of drugs to reach the receptor is obtained for?

Answer 25

pharmacokinetic parameters

Question 26

pharmacokinetics parameters characterize the;

Answer 26

absorption, distribution, and clearance of a drug

Question 27

phenomenon is referred to as ___________ in the concentration-effect relationship.

Answer 27

hysteresis

Question 28

observed of a drug such as digoxin

Answer 28

counterclockwise hysteresis loop

Question 29

which distributes slowly to its site of action

Answer 29

digoxin

Question 30

refers to the concentration or dose of a drug required to produce 50% of the drug's maximal effect.

Answer 30

potency

Question 31

how avidly the drug binds to the receptor

Answer 31

affinity

Question 32

occurs between receptor occupancy and response, which results in the EC50 for response being much less

Answer 32

signal amplification

Question 33

important only if it results in a need to administer the drug in large doses that are impractical

Answer 33

low potency

Question 34

for a quantal dose-response relationship is the dose at which 50% of individuals exhibit the specified quantal effect.

Answer 34

ED50

Question 35

also referred to as intrinsic activity. is the ability of drug to elicit a response when it binds to the receptor.

Answer 35

efficacy

Question 36

is the concentration of an antagonist that reduces a specified response to 50% of the maximal possible effect

Answer 36

median inhibitory concentration or IC50

Question 37

refers to a drug's ability to preferentially produce a particular effect and is related to the structural specificity of drug binding to receptors

Answer 37

selectivity

Question 38

a B-blocker, binds equally well to 1-adrenoreceptors

Answer 38

propranolol

Question 39

a B-agonist used for treating asthma. binds selectively to B2-adrenoceptors.

Answer 39

salbutamol