Drug Absorbtion 1

Question 1

Define Pharmaceutical Process?

Answer 1

Getting the drug into the patient

Question 2

What is it called “getting the drug to the site of action in the patient”?

Answer 2

The pharmacokinetic process

Question 3

What is the pharmacodynamic process?

Answer 3

Producing the correct Pharmocological effect with the drug.

Question 4

{What is the therapeutic process?

Answer 4

Producing the intended therapeutic response?

Question 5

What determines pharmacokinetics?

[ADME}

Answer 5

Absorption
Distribution
Metabolism
Elimination

Question 6

Define Absorption:

Answer 6

Process of movement of unchanged drug from site of administration to sytemic circulation.

Question 7

Try name 9 drug application routes. Go on i fucking dare you

Answer 7

Oral
Subcutaneous/Intramuscular
Inhalation/nasal
Transdermal (skin patches)
IV
Topical (creams etc)
Sublingul (under tongue)
Rectal

Question 8

Define therapeutic range:

Answer 8

The range of blood [drug] over which a drug is active

Question 9

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

Answer 9

If its above the range toxicity occurs

If its below the range theres insufficient pharmacological action

Question 10

Define Therapeutic Index (TI):

Answer 10

A comparison of the drug conc. level that causes the therapeutic effect against the amount that causes toxicity.

Question 11

What two things must you consider concernin the rate of oral absorption?

Answer 11

Amount of drug entering systemic circulation and speed at which it happens

Question 12

What is Tmax?

Answer 12

The time to peak drug conc. in systemic circulation

Question 13

What is Cmax?

Answer 13

The peak drug conc. in systemic circulation

Question 14

What is the AUC?

Answer 14

The area under a drug conc vs time curve.

I.e. the amount of drug reaching circulation

Question 15

How does increasing the dose affect Tmax & Cmax?

Answer 15

Increasing the Dose has no effect on Tmax but increases Cmax.

Question 16

Define Bioavailability?

Answer 16

Amount of Drug reaching circulation & available for action

Question 17

What method of drug administration has 100% bioavailability?

Answer 17

Intravenous Drugs have 100& bioavailability.

Question 18

What 4 factors effect Bioavailability?

Answer 18

• Formulation
• First pass metabolism
• Gastrointestinal effects
• Ability of drug to pass physiological barriers.

Question 19

How does formulation affect bioavailability?

Answer 19

Some drugs are prepared for slow release

Question 20

What 3 gastrointestinal effects alter bioavailability?

Answer 20

• Illness & Dsease
• Gut Motility
• Food

Question 21

What 3 areas affect the ability of a drug to pass physioloical barriers?

Answer 21

• pH & Ionisation
• Lipid Solubility
• Particle Size

Question 22

Define First pass metabolism?

Answer 22

The amount of drug metabolised by the gut before it is absorbed into systemic circulation

Question 23

What does passive diffusion rely on?

Answer 23

Lipid solubility

Degree of ionisation

Question 24

Why does drug ionisation affect passive diffusion?

Answer 24

Only unionised drugs can pass through membranes as ionised arnt lipid soluble

Question 25

What does the degree of ionisation rely on?

Answer 25

Local pH

i.e. an acidic drug will ionise in an alkaline enviroment

Question 26

What is the henderson-hasselbach equation used for?

Answer 26

The relationship between local pH and drug ionisation

Question 27

To what degree do pH changes affect drug ionisation?

Answer 27

Small pH changes can cause significant changes to drug ionisation & therfore diffusion rates.

Question 28

What is the lipid-water partition coefficient?

Answer 28

The ability of a drug to diffuse across a lipid barrier

ratio of drug dissovled in lipid vs water phase when in contact

Question 29

Exapli active absorption

Answer 29

Active absorption is unusual, occurs aainst the conc. gradient, is specific and requires carriers/energy.

Question 30

Example of drugs moved by active absorption:

Answer 30

Iron, potassium, sodium, calcium

Also levodopa uptake by the brain

Question 31

Explain Facilitated Diffusion:

Answer 31

Along conc. gradient
Needs carriers but not energy
Mizxed order kinetics

Question 32

Examples of drugs moved by facilitated diffusion:

Answer 32

Monosaccharides
AminoAcids
Vitamins

Question 33

What drives filtration/bulk flow across membranes?

Answer 33

Hydrostatic or osmotic pressure difference across the membrane

Question 34

How does Gut motility affect the rate of dru absorption?

Answer 34

The faster the gastric activity the faster the drug reaches the site of absorption

Question 35

What effects can food have on drug absorption?

Answer 35

Food can enhance or impair absorption of some drugs

Question 36

How can illness efect drug absorption?

Answer 36

Malabsorption can impair or inhance drug absorption rates

e..g caeliacs disease

Question 37

Define First pass metabolism:

Answer 37

Amount of drug metabolised prior to reaching the site of absorbtion

Question 38

How is drug metabolised in first pass metabolism?

Answer 38

By acids/enzymes in the gut lumen
By metabolic enzymes in the gut wall
By Hepatic enzymes in the liver

Question 39

What affects level of first pass metabolism:

Answer 39

The drug
Diseases
The person

Question 40

Descrive Intravenous drug administration:

Answer 40

• 100% bioavailability

- Avoids 1st pass metabolism

Question 41

Describe Topical drug Administration:

Answer 41

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

Question 42

Descrive Inhalation drug administration:

Answer 42

• 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 43

Describe the Hendersen-Hasselbach equation:

Answer 43

pH = pKa + log10 (ConjugateBase/UndissociatedAcid)