Pharmacology

Question 1

Pharmacodynamics is?

Answer 1

How the drug affects the body

Question 2

4 types of cellular receptors

Answer 2

Ligand gated ion channels
G-protein coupled receptors
Enzyme linked receptors
Intracellular receptors

Question 3

What is a ligand gated ion channel

Answer 3

Channel that opens briefly when a specific ligand binds to it

Question 4

How is a G protein coupled receptor activated

Answer 4

Ligand binds to outside of cell
GTP replaces the GDP attached to the alpha unit (inside the cell)
Alpha unit detaches and causes response

Question 5

How many subunits in a G-protein receptor

Answer 5

3

alpha, beta, gamma

Question 6

What is the final intracellular messenger from activating a G-protein receptor?

Answer 6

cAMP

Question 7

How many enzyme linked receptors have to be activated to produce a response?

Answer 7

2

Question 8

When 2 enzyme-linked receptors bind together, what is the result

Answer 8

They aggregate, form a dimer and then convert ADP to ATP

Question 9

Tyrosine kinase is a common example of which receptor type?

Answer 9

Enzyme linked receptor

Question 10

Describe the path a ligand takes to activate an intracellular receptor

Answer 10

Passes through cell membrane
Binds to receptor
Moves into nucleus
Causes synthesis of specific proteins

Question 11

What is EC50?

Answer 11

The dose required to produce 50% of the maximum pharmacological effect

Question 12

Is a higher or lower EC50 more potent?

Answer 12

Lower EC50 is more potent

Question 13

What is Emax

Answer 13

Maximum efficacy of the drug

All receptors are occupied by the drug

Question 14

What happens to a dose response curve with a competitive antagonist?

Answer 14

Shift it to the right

Question 15

3 types of antagonist?

Answer 15

Competitive, irreversible covalent and allosteric

Question 16

What happens to dose response curve with irreversible antagonist?

Answer 16

Moves it down, i.e. reducing the maximal efficacy

Question 17

How does the dose response curve change with allosteric antagonists?

Answer 17

It shifts it to the right

Question 18

How do you calculate therapeutic index?

Answer 18

Dose of that drug that causes toxicity in 50% of the population (TD50)
divided by
dose of that drug that causes therapeutic change in 50% of the population (ED50)

Question 19

What is pharmacokinetics

Answer 19

What the body does to the drug

Question 20

What are the 4 steps in pharmacokinetics?

Answer 20

ADME
absorption
distribution
metabolism
elimination

Question 21

4 methods of absorption

Answer 21

Passive diffusion
Facilitated diffusion
Active transport
Endocytosis

Question 22

Passive diffusion is what?

Answer 22

Drug moves through membrane down a concentration gradient

Question 23

What is facilitated diffusion?

Answer 23

Drug moves across membrane through specific membrane channels

Question 24

What is active transport?

Answer 24

ATPase membrane protein moves drug against concentration gradient

Question 25

What is endocytosis?

Answer 25

Cell membrane engulfing large molecules

Question 26

What is bioavailability?

Answer 26

How much drug makes it into the blood | Area under curve of oral drug divided by area under curve for IV drug multiplied by 100

Question 27

What is first order kinetics?

Answer 27

The drug is eliminated a certain % at a time and the concentration graph becomes a curve

Question 28

What is zero order kinetics?

Answer 28

Rate of elimination is constant, concentration graph becomes a decreasing straight line

Question 29

What is the steady state concentration?

Answer 29

After a certain number of doses, the elimination and absorbing of the drug becomes equal, the aim is to achieve this within the therapeutic range

Question 30

What type of drugs are less easily excreted by the kidney?

Answer 30

Lipid soluble

Question 31

What process happens to lipid soluble drugs before they can be excreted by the kidneys?

Answer 31

Transforming them into water soluble chemicals, through 2 reactions: phase 1 and phase 2

Question 32

3 types of phase 1 reactions?

Answer 32

oxidation hydrolysis reduction

Question 33

phase 2 reactions do what?

Answer 33

addition of a polar group

Question 34

Name 6 cytochrome P450 inhibitors (PCRABS)

Answer 34

``` Phenytoin Carbamazepine Rifampicin Alcohol Barbiturates St John's wort ```

Question 35

Name some cytochrome P450 inhibitors (G-PACMAN))

Answer 35

``` Grapefruit Protease inhibitors Azole antifungals Cimetidine Macrolides (except azithromycin) Amiodarone Non-DHP CCB's (diltiazem and verapamil) ```

Question 36

Name 4 common adverse effects of opiods

Answer 36

Constipation Nausea/vomiting Sedation Dry mouth

Question 37

Common dose of opiod to be given for breakthrough pain?

Answer 37

1/6th of the total 24h dose to be given PRN no more often than 2 hourly

Question 38

Name 5 anti-emetics

Answer 38

``` haloperidol levomepromazine metoclopramide domperidone ondansetron ciclizine ```