pharmacokinetics

Question 1

what is absorption

Answer 1

how the drug enters the bloodstream unless through intravenously where the drug typically moves through a semi permeable membrane till it reaches bloodstream

Question 2

describe the cell membrane

Answer 2

it is semi-permeable and is made up of a bilayer of phospholipids with a hydrophilic head and hydrophobic tail The bilayer is permeable to water and lipid soluble molecules but not large molecules and ions

Question 3

what is the point of a drug

Answer 3

. replace or act as a substrate for missing chemicals
. increase/ stimulate missing cellular activity
. depress/decrease cellular activity
.interfere with the functioning of foreign cells

Question 4

factors affecting pharmacokinetics

Answer 4

. age
. sex
. genetics
. organ function
. body composition

Question 5

passive diffusion

Answer 5

movement from high concentration to low concentration down a concentration gradient and requires no energy

Question 6

facilitated diffusion

Answer 6

uses plasma membrane proteins either as a channel or carrier protein

Question 7

leak channel

Answer 7

constantly open for substances to move in and out of

Question 8

gated channel

Answer 8

open for a brief moment before closing again

Question 9

carrier protein

Answer 9

molecules bind to the protein and if recognize will open otherwise

Question 10

active transport

Answer 10

going against a concentration gradient from low to high concentration which requires energy

Question 11

primary active transport

Answer 11

phosphate from ATP will bind to the molecule to supply it with energy

Question 12

secondary active transport

Answer 12

energy is supplied when another substance is moving down its concentration gradient

Question 13

pinocytosis

Answer 13

where fluids and substances are being ‘drank’ by the cell as the cell encloses the fluid or substance and fuses shut to form a vesicle into cell interior. (requires ATP as it is a form of active transport)

Question 14

why is drug dose form important

Answer 14

it affects rate and extent of absorption i.e. gases are absorbed faster and solid forms must be able to disintegrate for absorption

Question 15

what are the different form of drugs

Answer 15

.liquids- suspension, elixir and aqueous solutions
.solid- tablets, creams, capsules, ointments
.gases- anesthesia

Question 16

what is the importance of shape and sizes of drugs

Answer 16

smaller drugs penetrate faster than larger drugs

Question 17

How does lipid and water solubility affect a drug

Answer 17

most drugs are transported via simple diffusion and formulated to be lipid soluble to be able to penetrate through the phospholipid bilayer

Question 18

potential ionization

Answer 18

determines the rate at which a drug penetrates a cell membrane which determines the charge

Question 19

weak acidic drugs

Answer 19

best absorbed in areas with high acidity i.e. stomach

Question 20

weak base drugs

Answer 20

best absorbed in areas of low acidity i.e. intestine

Question 21

route of drug

Answer 21

the purpose of a drug is to have the fastest therapeutic effect with minimal side effects.

Question 22

the onset action of drug

Answer 22

length of time for drug to take affect

Question 23

Bioavailability

Answer 23

how long the dug stays in the body, rated from 0-100%

Question 24

First pass metabolism

Answer 24

drugs are metabolized in the liver before it can be distributed into the bloodstream which decreases the concentration of the drug

Question 25

diet

Answer 25

can disturb absorption by delaying gastric emptying time, altering gastrointestinal pH or physically interacting with drug. Therefore drugs sometimes prescribed with ‘with’ and ‘without’ food.

Question 26

Distribution

Answer 26

Drugs are absorbed the the blood stream by attaching to the receptor sites

Question 27

why do you experience side effects

Answer 27

because it is difficult for the body to target specific tissue

Question 28

Blood flow

Answer 28

some organs of the body receive more blood flow i.e. heart, brain, liver, etc. than the other organs i.e. skin, muscle, fat.

Question 29

Physical properties of drug

Answer 29

lipid soluble drugs tend to be absorbed faster and can build up on fatty tissue while water soluble drugs are more concentrated in blood and interstitial fluid

Question 30

Blood brain barrier

Answer 30

capillaries in the brain are surrounded by simple squamous epithelium and astrocytes making it harder for drugs to penetrate past the barrier so they are made to be more lipid soluble

Question 31

Plasma protein binding

Answer 31

the extent to which a drug is binding to a protein in blood plasma

Question 32

bound

Answer 32

the portion of the drug that is binding to the protein

Question 33

unbound

Answer 33

the rest of the portion of the drug which has not bound with the protein

Question 34

loading dose

Answer 34

when a higher concentration of a drug is administered to have a therapeutic effect or create an immediate response

Question 35

volume of distribution

Answer 35

how much a drug needs to be within the body to get a certain concentration within the plasma

Question 36

volume of distribution equation

Answer 36

TOTAL AMOUNT OF DRUG IN THE BODY/CONC OF DRUG IN PLASMA.

Question 37

metabolism

Answer 37

the biotransformation of a drug into a substance that is more water soluble

Question 38

Metabolism 1 (Modification)

Answer 38

undergoing chemical reactions using Cytochrome P-450 to make drug more water soluble

Question 39

Metabolism 2 (Conjugation)

Answer 39

The active part of the drug fuses with another component to become more water soluble

Question 40

Excretion

Answer 40

to prevent the increase in therapeutic or unwanted toxic effects