Pharmokinetics

Question 1

What is pharmokinetics ?

Answer 1

The study of drug movement throughout the body
What happens to drug as it moves through the body

Question 2

why is it important to know pharmokinetics ?

Answer 2

help maximize beneficial effects and minimize harm

Question 3

What do all phases of pharmokinetics require ?

Answer 3

movement- get to the site of action , get to site of metabolism, get to site of elimination

Question 4

What are the 3 ways a drug can pass through a cell membrane ?

Answer 4

1. through channels and pores ( small compounds like minerals and electrolytes )
2. Passage using transport systems ( PGP=P glycoprotein , multi drug transporter
3. direct penetration of membrane - most common way but drug has to be lipid soluble, meaning lipophilic

Question 5

Ions are molecules that contain

Answer 5

a net electrical charge

Question 6

what is a quaternary ammonium compound ?

Answer 6

will always have a positive charge and will contain at least one atom of nitrogen

Question 7

What is pH dependant ionization ?

Answer 7

Acid is a proton donor ,will ionize to basic ( alkaline )
Base is a proton acceptor , will ionize in acidic media

Question 8

What is pH partitioning ?

Answer 8

AKA ion trapping, acidic drugs accululate on the alkaline side, basic drugs accumulate on the acidic side

Question 9

what is absorption ? and what will it determine ?

Answer 9

movement of a drug from administration site to the blood, it will determine how soon there will be effects and the amount will show how intense these effects will be

Question 10

what are some of the factors that will impact drug absorption ?

Answer 10

Rate of dissolution
Surface area
Blood flow
Lipid solubility
pH partitioning (Ion trapping

Question 11

What are the enteral routes of administration ?

Answer 11

sublingually, oral( most preffered) and rectal

Question 12

what are the parenteral routes of adminstration ?

Answer 12

intravenously, intramuscularly, subcutaneously

Question 13

oral administration is usually in the form of ?

Answer 13

tablets, enteric coated preparations, sustained release preparations

Question 14

distribution is ?

Answer 14

movement of drug throughout the body

Question 15

the blood flow will determine ?

Answer 15

The rate of delivery of the drug

Question 16

how can abscesses and tumours impact drug distribution

Answer 16

solid tumours have limited blood supply and low limited blood flow will impact therapy

Question 17

with capillary beds, drugs will pass which way ?

Answer 17

They will pass between capillary beds instead of through them to exit the vascular system

Question 18

What is the problem with the placenta for drug transfer ?

Answer 18

membranes of the placenta are not an absolute barrier to drugs, movement is the same as other membranes

Question 19

what is the most important plasma protein for drugs ? why is this ?

Answer 19

albumin, which always remains in the blood stream and can impact drug distribution and can result in drug interactions leading to toxicity

Question 20

true or false drugs can form irreversible bonds with some proteins ?

Answer 20

FALSE - drugs can form reversible bonds with some proteins

Question 21

most drugs must enter cells in order for what to take place ?

Answer 21

metabolism and excretion

Question 22

true or false, some drugs must enter the cell in order to each the site of action ?

Answer 22

True

Question 23

do drugs need to cross the cell membrane to access the receptors ?

Answer 23

No because they are located usually on the surface of the membrane

Question 24

one of the most common ways drugs produce their effects is by ?

Answer 24

bind to the receptors on the external surface on the membrane

Question 25

what is another name for drug metabolism ?

Answer 25

bio transformation ( when the chemical structure of the drug is altered

Question 26

biotransformation takes place where

Answer 26

Usually in the liver

Question 27

cytochrome P450 is what ?

Answer 27

enzyme needed to metabolize drugs in the liver

Question 28

what are some of the consequences of drug metabolism ?

Answer 28

Drug inactivation Increased therapeutic action Activation of prodrugs Increased or decreased toxicity Accelerated renal drug excretion- *Most important*

Question 29

What is enterohepatic re circulation

Answer 29

Repeating cycle in which drug is transported From the liver into the duodenum (via the bile duct) Back to the liver via the portal blood

Question 30

enterohepatic recirculation happens only with drugs that have

Answer 30

have undergone glucuronidation

Question 31

What should be considered for drug metabolism ?

Answer 31

Age( older adults have a slower metobolims, kids have not yet fully developped the liver so they are more sensitve to drugs Induction of drug-metabolizing enzymes P450 inducers – INCREASE Metabolism P450 inhibitors – DECREASE Metabolism First-pass effect Nutritional status Competition among drugs

Question 32

What is excretion ?

Answer 32

This can be defined as Removal of drugs from the body

Question 33

What are some of the ways drugs can exit the body ?

Answer 33

through urine, sweat, saliva, breast milk, or expired air

Question 34

Organ responsible for excretion ?

Answer 34

the kidneys

Question 35

What are the steps in renal drug excretion ?

Answer 35

Glomerular filtration Passive tubular reabsorption Active tubular secretion

Question 36

factors that can modify renal excretion ?

Answer 36

pH-dependent ionization Competition for active tubular transport Age

Question 37

What are the non renal route of drug excretion

Answer 37

Lungs (especially anesthesia) Sweat/saliva (small amounts) Bile breast milk

Question 38

What is the half life of a drug ? what does it determine?

Answer 38

Defined as the time required for the amount of drug in the body to decrease by 50%- will determine the dosing interval

Question 39

duration of effects is determined by ?

Answer 39

combination of metabolism and excretion

Question 40

drugs that are above the minimum effecrive dose, there will be ?

Answer 40

a maintenance of the therapeutic response

Question 41

drug levels produced with repeating doses

Answer 41

still unlcear on the graph