PBL workshop (1st)

Question 1

what defines the relationship between the administration of a drug, the time-course of its distribution, and the concentration attained in different regions of the body (effects of body on drug)

Answer 1

pharmacokinetics

Question 2

what is the quantitative description of the biochemical and physiological effects of drugs and the mechanisms underlying these effects (effects of drug on body)

Answer 2

pharmacodynamics

Question 3

what is the threshold PC (enough drug enters tissues to interact with receptors and produce effect)

Answer 3

minimal effect concentration (MEC)

Question 4

what is the driving force for lipid diffusion

Answer 4

concentration gradient

Question 5

what is the driving force for aqueous diffusion

Answer 5

concentration gradient

Question 6

what is the rate of diffusion equation

Answer 6

(available surface area X concentration gradient) / (resistance of membrane X thickness of membrane)

Question 7

what environment do acids readily denote proteins and become deprotonated

Answer 7

aqueous solutions

Question 8

what happens to a base when put in an aqueous solution

Answer 8

becomes ionized when protonated (accepts protons)

Question 9

are weak acids excreted faster in alkaline or acidic environment

Answer 9

alkaline

Question 10

are weak bases excrete faster in acidic or alkaline environment

Answer 10

acidic

Question 11

what does sodium bicarbonate increase the excretion of

Answer 11

weak acids

Question 12

what does ammonium chloride increase in the excretion of

Answer 12

weak bases

Question 13

what is the bioavailability for drugs applied IV route

Answer 13

100%

Question 14

what is the bioavailability for drugs applied subcutaneously

Answer 14

75-100%

Question 15

what is the bioavailability for drugs applied orally

Answer 15

5-100%

Question 16

what is the bioavailability for drugs applied rectally

Answer 16

30-100%

Question 17

what is the bioavailability for drugs applied through inhalation

Answer 17

5-100%

Question 18

what is the bioavailability for drugs applied transdermally

Answer 18

80-100%

Question 19

what must be true for bioequivalence

Answer 19

same active ingredients, identical strength/concentration, dosage form and route of administration must be the same

Question 20

what drugs may cross the BBB

Answer 20

low MW (200-300 Da) and lipid soluble drugs

Question 21

what is the most important plasma protein

Answer 21

albumin

Question 22

what drugs (in general) bind primarily to albumin

Answer 22

acidic drugs and some neutral compounds

Question 23

what drugs bind more primarily to alpha-acid glycoprotein (AAG)

Answer 23

more basic drugs (lidocaine, quinidine, propranolol)

Question 24

common places of drug loss (areas where drug is not used or has no effect)

Answer 24

fat, GI tract, others

Question 25

what is the equation for volume of distribution

Answer 25

dose/plasma drug concentration

Question 26

what are some factors that influence volume of distribution

Answer 26

plasma protein binding, lipid solubility, organ/tissue specific accumulation

Question 27

what type of reactions occur with phase 1 reactions

Answer 27

oxidation/reduction reactions

Question 28

what type of reactions occur with phase 2 reactions

Answer 28

conjugation/hydrolysis reactions

Question 29

what is the principle organ of drug metabolism

Answer 29

liver

Question 30

what is the location of cytochrome P-450 enzymes

Answer 30

smooth ER of hepatocytes and intestinal epithelia

Question 31

what is the number one role of P450 system

Answer 31

metabolism and detoxification of substances

Question 32

what are some inducing agents for the 3A4 cyp-450 isozyme

Answer 32

carbamazepine and phenobarbitol

Question 33

what are some substrates that correlate with the inducing agents of 3A4 isozyme

Answer 33

alprazolam and erythromycin

Question 34

what are some inhibiting agents of the 3A4 isozyme of CYP-450

Answer 34

cimetidine and grapefruit juice

Question 35

what are some substrates that go along with the inhibiting agents of 3A4 isozyme

Answer 35

midazolam and atorvastatin

Question 36

what happens to bioavailability when an inhibiting substrate is used

Answer 36

increased bioavailability

Question 37

what is rate of elimination dependent on

Answer 37

rate of biotransformation and rate of excretion by one or more routes

Question 38

what happen to rate of elimination if drug concentration is high

Answer 38

rate of elimination is rapid

Question 39

what happens to rate of elimination if drug concentration is low

Answer 39

rate of elimination is slow

Question 40

what is the equation to determine half-life (1st order)

Answer 40

(0.7 X Vd) / CL

Question 41

what are some zero-order kinetic drugs

Answer 41

ETOH, aspirin and phenytoin

Question 42

where in the kidney does filtration of drugs occur

Answer 42

glomerulus

Question 43

where in the kidney does tubular secretion of drugs occur

Answer 43

proximal tubule

Question 44

where in the kidney does reabsorption of drugs occur

Answer 44

into renal capillaries

Question 45

what is the equation for Css

Answer 45

infusion rate / clearance

Question 46

when is 94% of the steady state of Css reached

Answer 46

4 half lives

Question 47

what is the equation for loading dose

Answer 47

(Vd X Ct) / F