definitions

Question 1

clearance

Answer 1

relationship between drug concentration to the rate of elimination (rate out)

Question 2

volume of distribution

Answer 2

relationship between concentration and the amount of a drug in the body

Question 3

extend of absorption

Answer 3

reflects total amount of drug entering the body, is not time-dependent

Question 4

rate of absorption

Answer 4

determines how quickly the drug enters the body. The rate typically changes with time.

Question 5

fraction absorbed

Answer 5

how much of the drug gets from the gut into the portal venous system

Question 6

first pass extraction

Answer 6

determined by blood flow and organ clearance

e.g. hepatic = amount of drug removed while passing through the liver

Question 7

zero order input

Answer 7

means the absorption rate is constant for a defined period of time. Achieved by a constant rate IV infusion

Question 8

first order input

Answer 8

means the absorption rate is proportional to the amount or concentration of drug at the absorption site. An example is an intra-muscular injection of a drug.

Question 9

bolus input

Answer 9

absorption is instantaneous. Is approximated by rapid intravenous injection

Question 10

half-life

Answer 10

the time taken for a concentration of a drug to fall to half its value. Describes first order process, which describes absorption and elimination

Question 11

accumulation factor

Answer 11

is the ratio of the concentration at steady state to the concentration after the first dose at the same time after the dose.

Question 12

affinity

Answer 12

a measure of how tightly a drug binds to a receptor.

Kd = concentration when 50% of the receptors are occupied. Higher Kd means lower affinity

Question 13

potency

Answer 13

a measure of how much drug is required to produce a particular effect. EC50

Question 14

efficacy

Answer 14

is the ability of a drug to produce a response. Emax

Question 15

receptors

Answer 15

proteins which specifically recognise a particular neurotransmitter/hormone and upon binding undergo a conformational change leading to activation/inhibition of cell signalling.

types:

• ligand gated ion channels
• g-protien coupled receptors
• nuclear receptors
• tyrosine kinase receptors

Question 16

full agonists

Answer 16

drugs that elicit the maximum tissue response

Question 17

partial agonists

Answer 17

drugs that produce less than the maximal response

Question 18

antagonists

Answer 18

a compound that binds to a receptor but does not activate or inactive the receptor
have affinity but no efficacy

Question 19

irreversible antagonists

Answer 19

drugs that covalently bind to a receptor. They reduce the number of receptors available to the agonist

Question 20

pharmacogenomics

Answer 20

the investigation of variations of DNA and RNA characteristics as related to drug response

Question 21

drug interaction

Answer 21

a change in one drugs effect when administered with another drug, food or other substance

Question 22

pharmacokinetic interactions

Answer 22

Drug-drug interactions that alter the plasma concentration of 1 or both drugs. Can occur at the level of absorption, distribution, metabolism or elimination

Question 23

pharmacovigilance

Answer 23

monitoring of the safety of marketed medicines and taking action to reduce risk and promote safe use, thereby protecting public health

Question 24

special authority medicines

Answer 24

prescriber requests government subsidy for a particular individual

Question 25

specialist only medicines

Answer 25

only subsidised if prescribed by the appropriate specialist

Question 26

surrogate

Answer 26

biomarker used for regulatory approval

Question 27

biomarker

Answer 27

readily measurable marker of response

Question 28

adverse drug reaction

Answer 28

a response to a drug which is noxious and unintended, and which occurs at doses normally used.

Question 29

side effect

Answer 29

an expected and known effect of a drug that is not the intended therapeutic outcome.

Question 30

target concentration intervention

Answer 30

links pharmacokinetics and pharmacodynamics to predict the right dose for a patient

Question 31

rational prescribing

Answer 31

selection of the most appropriate therapeutic regimen for a specific patient

Question 32

selective toxicity

Answer 32

is the goal of chemotherapy
achieved by exploiting differences between normal host cells and disease producing cells, when:

• there is a unique target in the pathogen
• the target is structurally different in the pathogen
• the target is functionally different in the host

Question 33

therapeutic index

Answer 33

(important indicator for selective toxicity)

ratio of dose required to produce toxic effect divided by the dose required to produce desired effect

Question 34

targeted cancer therapy

Answer 34

drug treatments that inhibit oncoproteins that drive tumour development and progression