Clinical pharmacology

Question 1

what is the definition of pharmacokinetics?

Answer 1

what the body does to the drug

Question 2

what is the definition of pharmacodynamics?

Answer 2

what the drug does to the body

Question 3

what is the absorption rate for intravenous (IV)?

Answer 3

100%

Question 4

what is the absorption rate for oral intake?

Answer 4

it is variable, depends on absorption of medicine and form of medicine, usually requires a higher dose for oral intake than for IV

Question 5

what is the definition of bioavailability (F or BB)?

Answer 5

the fraction of an administered dose of unchanged drug that reaches the systemic circulation

Question 6

what is the ADME process?

Answer 6

Absorption, distribution, metabolism, elimination

Question 7

name the 4 places where the medication can spread to

Answer 7

1. hydrophilic (watery) tissues; blood and muscles
2. lipophilic (fatty) tissues; dermis, nerves and fat tissues
3. brain; through the blood brain barrier
4. placenta/breastmilk

Question 8

what is the formula for volume of distribution?

Answer 8

Vd = Ab (quantity of drug in the body) / C (concentration in the blood)
Vd = F * dose / plasma concentration

Question 9

which one has a small and large Vd? lipophilic or hydrophilic substances?

Answer 9

Lipophilic substances; large Vd
Hydrophilic substances; small Vd

Question 10

what is the definition of metabolism, where and why does it happen?

Answer 10

chemical conversion in the body (biotransformation), liver via CYP450, drug must be converted to a water soluble form (metabolites) to be excreted by the kidneys

Question 11

true or false? genetic polymorphisms or drug-drug interactions can speed up, slow down or change the normal breakdown of the drug

Answer 11

true

Question 12

which enzyme is responsible for metabolizing codeine into morphine in the liver?

Answer 12

CYP2D6

Question 13

describe what happens when fast metabolizers get a normal dose of codeine

Answer 13

metabolize codeine into morphine faster and more completely, resulting in high morphine concentration and higher effect

Question 14

what is the definition of elimination?

Answer 14

elimination of substance from the body via urine, bile and feces

Question 15

true or false? in the case of decreased renal function, drug dose needs to be decreased

Answer 15

true

Question 16

what is the definition of intra-patient and inter-patients?

Answer 16

intra-patient; one person reacts differently to the same medication in multiple or repeated dosings (within)
inter-patient; differences between a group in how individuals react to a medication (between)

Question 17

what is drug clearance?

Answer 17

the volume of plasma cleared of the drug per unit time

Question 18

what is half-life (T1/2)?

Answer 18

time necessary to decrease the blood concentration of a medication by 50%

Question 19

what are the formulas of when medication is out of the blood and a steady level?

Answer 19

4-5x T1/2
3-5x T1/2

Question 20

what is AUC?

Answer 20

area under the curve = exposure to the drug (when plasma drug concentration is plotted versus time)

Question 21

what is the definition of pharmacogenetics?

Answer 21

DNA analysis to explain/predict the response of patient to drug therapy

Question 22

name 3 factors which determines the effect of drugs

Answer 22

1. dose
2. kidney function
3. liver enzymes (CYP)

Question 23

what is the definition of therapeutic window?

Answer 23

dose-dependent to have positive effect per individual

Question 24

name 5 examples of drugs that need to be inactivated, do UM and PM need a higher or lower drug dose?

Answer 24

CYP2D6; imipramine
CYP2D6; metoprolol
CYP2C19; voriconazol
CYP3A4/4; tacrolimus
TMPT; azathioprine
UM: higher dose
PM: lower dose

Question 25

name 3 examples of drugs that need to be activated, do UM and PM need a higher or lower drug dose?

Answer 25

CYP2D6; codeine
CYP2D6; tamoxifen
CYP2C19; clopidogrel
UM: lower dose
PM: higher dose