drug absorption

Question 1

what is the pharmaceutical process ?

Answer 1

getting the drug into the patient

Question 2

what is it called when u ‘get the drug to the site of action in the patient’?

Answer 2

pharmokinetic process

Question 3

what determines pharmokinetics ?

Answer 3

ADME

absorption
distribution
metabolism
elimination

Question 4

define absorption

Answer 4

movement of UNCHANGED drug from its site of administration to the systemic circulation

Question 5

what is the pharmacodynamic process

Answer 5

producing the correct pharmacological effect with the drug

Question 6

what is the therapeutic process ?

Answer 6

producing the intended therapeutic response

Question 6

be familiar with the 9 drug application routes

Answer 6

IV & IM (intravenously ,muscularly
rectal
sublingual (under the tongue)
topical
transdermal (skin patch)
inhilation/nasal

Question 7

what is meant by therapeutic range

Answer 7

the range of blood over which a drug is active

Question 8

what happens if drug conc is above or below the therapeutic range ?

Answer 8

if its above then toxicity ocurs

if below then insufficient pharmocological effects occur

Question 9

what is therapeutic Index (TI)

Answer 9

a comparison of drug concentration

compares the dose that causes therapeutic effects against the dose that causes toxicity

Question 10

what 2 things must you consider concerning the rate of oral absorption of a drug

Answer 10

the amount of drug entering the systemic circulation

the speed at which it happens

Question 11

what is Tmax and Cmax?

Answer 11

Tmax- time at which maximum concentration occurs

Cmax- maximum concentration of drug in the body

Question 12

where does the Tmax and Cmax occur in the body

Answer 12

in systemic circulation

Question 13

what is the AUC? and what does it show

Answer 13

area under curve (of a tmax & cmax curve)
the amount of drug reaching circulation

Question 14

state the effect on increasing dose & root adminintration on Cmax and Tmax

Answer 14

increases Cmax

no effect on Tmax

Question 15

define bioavailability

Answer 15

amount of drug reaching circulation

Question 16

What method of drug administration has 100% bioavailability?

Answer 16

intravenous drugs

Question 17

What 3 factors effect Bioavailability?

Answer 17

-solubility (hydrophobic and small drugs easily pass through membrane therefore bioavailability increases & vice versa)

-formulation (environment it gets absorbed in)

-first pass metabolism

Question 18

What 3 gastrointestinal effects alter bioavailability?

Answer 18

-food
-illness & disease
-gut motility

Question 19

define first pass metabolism

Answer 19

when a drug goes into the gastrointestinal tract before reaching the systemic circulation

Question 20

what drug administration goes through first pass metabolism

Answer 20

oral administration

Question 21

what does passive diffusion rely on ?

Answer 21

degree of ionisation
solubility (hydrophobic and small)

Question 22

can ionised and unionised drugs pass the membrane

Answer 22

ionised drugs cannot as theyre are not lipid soluble

unionised ones can

Question 23

What is the henderson-hasselbach equation show?

Answer 23

relationship between local Ph and drug ionisation

pH = pKa + log10

Question 24

how does ph affect drug ionisation?

Answer 24

small ph change would have a significant change to drug ionisation (for example an acid drug will ionise in an alkaline environment)

Question 25

explain active absorption

Answer 25

occurs against conc graident and needs carriers & energy

Question 26

give example of drugs moved by active absorbance

Answer 26

potassium, sodium,calcium,iron also levodopa

Question 27

Explain Facilitated Diffusion

Answer 27

moves along conc gradient uses carriers and NO ENERGY

Question 28

give 3 examples of drugs moved by facilitated diffusion

Answer 28

-amino acids -vitamins -monosaccharides

Question 29

what drives the flow across membrane

Answer 29

osmotic or hydrostatic pressure

Question 30

state the effects food and ilness have on drug absorption

Answer 30

food and illness can enhance or repair absorption of some drugs

Question 31

Descrive Intravenous drug administration:

Answer 31

100% bioavailability Avoids 1st pass metabolism

Question 32

Describe Topical drug Administration:

Answer 32

Can achieve local or systemic effects Can achieve controlled, sustained doses of drugs Avoids 1st pass metabolism

Question 33

Descrive Inhalation drug administration:

Answer 33

Drug delivered directly to site Rapid effect Small doses needed Reduced adverse effects Metabolised in lungs so only 5-10% is absorbed. (little systemic effecT)

Question 34

How is drug metabolised in first pass metabolism?

Answer 34

by enzymes in the gut lumen and wall by enzymes in the liver (hepatic enzymes)

Question 35

Pka value should be closest to the ph when choosing ur answer, true or false

Answer 35

true

Question 36

what is drug therapy

Answer 36

to achieve efficacy without toxicity

Question 37

why do most drugs not ionise completly in water

Answer 37

cus theyre weak bases or acids