Drug Toxicity

Question 1

ED50, TD50, and LD50 all occur in what type of subjects?

Answer 1

live subjects

Question 2

What is the median effective dose, dose that produces a response in 50% of the population, produces 50% of maximal effect?

Answer 2

ED50

Question 3

What is the dose required to produce a toxic effect in 50% of the population?

Answer 3

TD50

Question 4

What is the dose required to kill 50% of the population (animals)?

Answer 4

LD50

Question 5

What measures drug safety and can be found by TD50/ED50 or LD50/ED50?

Answer 5

therapeutic index (TI)

Question 6

What does a high TI mean?

Answer 6

safer drug

Question 7

If TI is 4, what does that mean?

Answer 7

only takes 4x the regular dose to produce a toxic/lethal response

Question 8

What is the minimum effective dose to minimum toxic dose; doses in this range are effective and essentially free of side effects?

Answer 8

therapeutic window

Question 9

What is the range from where a drug begins to work to when adverse effects begin but has some overlapping?

Answer 9

therapeutic window

Question 10

What describes proteins or glycoproteins on surface of a cell, on an organelle, or in the cytoplasm designed to bind to endogenous substances?

Answer 10

drug receptors

Question 11

When a drug or endogenous ligand reaches a receptor, what changes can occur?

Answer 11

• opening/closing of ion channel
• formation of biochemical messengers
• inhibition of normal cellular functions
• increase in cellular activity

Question 12

There are only so many receptors in the body, so what can occur?

Answer 12

saturation (can lead to no more effect of drug on patient)

Question 13

Drugs may be what for receptors?

Answer 13

selective (only binding to certain receptors) or non-selective (binds to everything)

Question 14

If a drug binds to somewhere other than its intended site, what happens?

Answer 14

it is ineffective, no use

Question 15

Unbound drug concentrations are important why?

Answer 15

this is the portion of drug free to interact with its target site

Question 16

Drugs do not add what when interacting with the receptor?

Answer 16

a new function
NEVER a new function
- can be turned on, turned off, or attentuated

Question 17

What are active receptors that possess affinity and activity (potent and effective)?

Answer 17

agonist

Question 18

What creates a similar response to your biological function?

Answer 18

agonists

Question 19

What are the different type of agonists?

Answer 19

• full agonists
• partial agonists
• inverse agonists

Question 20

What type of agonists produce a max response and show full efficacy?

Answer 20

full agonists

Question 21

What type of agonists never reach Emax so they have some efficacy but not full?

Answer 21

partial agonists

Question 22

What type of agonist produce an effect opposite that of the natural ligand (basil function that is shut off and not producing)?

Answer 22

inverse agonist

Question 23

What binds to receptors to block the binding of other substances?

Answer 23

antagonist

Question 24

What prevents an action from occurring?

Answer 24

antagonist

Question 25

What must be present or else an antagonist is not active and producing a neutral effect?

Answer 25

agonist

Question 26

What possessed affinity (potency) but not activity (efficacy)?

Answer 26

antagonists

Question 27

What type of antagonists compete for the same binding site as the agonist and is a reversible process?

Answer 27

competitive antagonist

Question 28

With competitive antagonists, the dose-response curve shifts?

Answer 28

right (becomes less potent, EC 50 changes)

Question 29

What can you add to a system to overcome a competitive antagonist?

Answer 29

add more agonist

Question 30

What type of antagonist binds to the same site as an agonist using covalent bonding so it is permanent and irreversible?

Answer 30

noncompetitive antagonists

Question 31

What reduces the effect of an agonist since there is a reduction in the amount of sites that agonists can bind to?

Answer 31

noncompetitive antagonists

Question 32

What describes binding to a site other than the agonist binding site resulting in a conformational change and what is this associated with?

Answer 32

- allosteric - noncompetitive antagonists

Question 33

How can you overcome noncompetitive antagonists?

Answer 33

add more binding sites, not more agonists

Question 34

What acts as competitive antagonists in the presence of an agonist?

Answer 34

weak partial agonist

Question 35

Weak partial agonists have some activity (efficacy) but it is opposite of what?

Answer 35

agonists

Question 36

When you add weak partial agonists, it will be harder for what to bind so you will get a decrease in?

Answer 36

harder for agonists to bind so you will get a decrease in efficacy