Apex- Pharmacodynamics

Question 1

Pharmacokinetics

Answer 1

What the BODY does to the drug

Question 2

Pharmacodynamics

Answer 2

What the Drug does to the body

> potency, efficacy, dose-response curve slope, agonist, antagonist, ED50, LD50, Theraputic index, stereochemistry

Question 3

Chemistry term to describe the drugs specific shape, size, and characteristics which allow it to bind to a certain receptor.

Answer 3

Stereospecificity

Question 4

A drug that binds to a receptor and fully enhances the response of that receptor

Answer 4

Full agonist

Question 5

A drug that sit’s on a specific receptor, doesn’t activate it, but blocks an agonist from binding to it.

Answer 5

Antagonist

> it doesn’t tell the cell to do anything

Question 6

Difference between competitive and non-competitive antagonists

Answer 6

1. Competitive = reversible ; wants to compete, can lose and be overridden by increasing concentrations of agonists
   * Rocuronium competes with ACH at the NMJ
2. Noncompetitive = irreversible binding; “not worth my time to even compete with you, I sit and stay, I win, you lose”
   * Aspirin inhibits the Cox-1 enzyme fro the entire life of the platelet (7-10days)

Question 7

If the patient receives a competitive antagonists, will the dose-response curve shift to the right or left?

Answer 7

Right > because it will require MORE of the AGONIST to exert it’s effects

Question 8

What happens with the dose response curve with noncompetitive agonists?

Answer 8

It shifts down and resembles a partial agonist

Question 9

What might continuous administration of an agonist cause? Up or down regulation of receptors?

Answer 9

Down regulation - body senses the overstimulation of the target receptors and tries to fix it by not producing as many receptors

Question 10

Continuous administration of an antagonist may cause up/down regulation of receptors?

Answer 10

Up-regulation. Body senses under stimulation of these receptors and wants to equilibrate by making more receptors

Question 11

What law describes a drug binding to a receptor?

Answer 11

The law of mass action

Question 12

Partial agonist AKA: ________
Example
How does it work

Answer 12

Agonist-Antagonist
Ex. Suboxone/ Nalbuphine
Binds to a receptor and PARTIALLY turns it on
>can block the effects of agonist by competing for binding sites

Question 13

What kind of drug binds to a receptor and directly causes the opposite effect of a full agonist
Example?

Answer 13

Inverse agonist

(Not antagonist bc the antagonists just sit there and don’t cause any effect directly)

Epi- full agonist- binds to B1 > increased cAMP
Propranolol- inverse agonist - binds to B1- decreased levels of cAMP

Question 14

Chemical term to describe a drug that binds in one place but works somewhere else

Answer 14

Allosteric

Question 15

Dose- response curve: what represents how many of the receptors must be occupied to exert a clinical effect?

Answer 15

The slope

Question 16

Dose response curve: what represents the dose required to achieve the clinical effect? X or Y axis

Answer 16

X-axis (bottom/horizontal) (slope)

Question 17

Dose-response curve- which part represents the ability of the drug itself to elicit a clinical effect? X or Y axis

Answer 17

The Y-axis (vertical)

Question 18

What is ED50 vs ED90?

Answer 18

The dose required to elicit a given clinical effect in 50%/90% of the population

(Dose response curves)

Question 19

With dose-response curves, once the plateau phase is reached, what would happen if you give more drug? Would it increase the effect?

Answer 19

No increase in effect , just increase in risk of toxicity

Question 20

Which drug is more potent (see dose response curve pic)

Answer 20

Drug A - less dose (x/bottom axis) is required to achieve the same effect of drug B

Question 21

With a dose-response curve, if the drug has an increased affinity for the receptor, which way will it shift?

Answer 21

To the left

>increased affinity = increased receptors to occupy to elicit the response

Question 22

See this dose-response curve. If these drugs are narcotics, what assumptions can be made about drugs A and B

Answer 22

Both drugs elicit a response but drug A elicits a greater response (greater analgesia)

Question 23

Which goes where ? Agonist, Inverse agonist, partial agonist, antagonist

Answer 23

Agonist - binds and enhances normal response
Partial agonist- binds and half ass enhances the normal response
Antagonist - binds to a receptor and prevents binding from other agents
*DOES NOT DIRECTLY EVOKE A CLINICAL RESPONSE!
Inverse agonist- binds to a receptor causing the opposite effect of its normal response
Ex) H1 & H2 blockers

Question 24

How is the therapeutic index of a drug measured?

Answer 24

LD50/ED50

• ED50 - dose of a drug that elicits the intended clinical effect in 50% of the population
• LD50 - dose of a drug that will kill 50% of the population

Question 25

What is the ED50 a measure of?

Answer 25

Potency

Question 26

What is a division of stereochemistry where the molecules have a center of 3-dimensional asymmetry? What does the asymmetry stem from?

Answer 26

Chirality | -asymmmetry stems from the tetrahedral bonding of a carbon

Question 27

A molecul with 1 chiral carbon will exist as how many enantiomers?

Answer 27

Two >the more chiral carbons in a molecule, the more enantiomers

Question 28

What are chiral molecules that are non-superimposable, mirror images of one another?

Answer 28

An Enantiomers

Question 29

``` Dextrorotary vs levorotarory enantiomers. Which one is: +/- R/S Clockwise/counterclockwise ```

Answer 29

DEXTRO + R Clockwise > think if you see DEXTER, your time (clockwise) is positively Running out LEVO - S Counterclockwise >think Levo loves being Silly (counterclockwise) , negative spin

Question 30

What kind of mixtures contain 2 enantiomers in equal amounts?

Answer 30

Racemic mixture

Question 31

About how many of the drugs we administer are enantiomers? How many of them are prepared as racemic mixtures? Exceptions (2)

Answer 31

1/3 are enantiomers Almost all of them are prepared as racemic mixtures Except : Levobupivacaine & Ropivacaine (Single enantiomers) (LEaVe the ROPe)

Question 32

12 Racemic mixtures

Answer 32

``` Bupivacaine Desflurane Isoflurane Ibuprofen Ketamine Ketorolac Methohexital Methadone Morphine Mepivacaine Prilocaine Thiopental ```

Question 33

Is S-Bupivacaine more or less toxic than R-bupivacaine or the racemic mixture?

Answer 33

S-Bupivacaine = Levo-bupivacaine Levo, Less cardiotoxic