Drug Distribution

Question 1

what are the factors affecting tissue distribution

Answer 1

tissue permeability

plasma protein binding

binding to cellular components

blood flow

Question 2

discuss BF to liver

Answer 2

more BF despite being small

more drugs go to liver = main organ for metabolism

drugs can be toxic to liver

Question 3

discuss BF to brain

Answer 3

more BF than muscle tissue

s BBB toxic effects can be felt sa brain kaagad

Question 4

what is volume of distribution

Answer 4

apparent space in body available to contain drug

amt of drug/concentration in plasm

low plasma volume = lower doses

Question 5

discuss large volume of distribution

Answer 5

higher tissue concentration and lower in plasma = longer duration

less na mmetabolize sa plasma

Question 6

discuss small volume of distribution

Answer 6

low in tissue and higher in plasma = more drug is eliminated

Question 7

purpose of volume of distribution

Answer 7

allows estimate for dosage and recover

determines therapeutic vs toxic dose in normal pt and pt c problems

compares drugs

Question 8

discuss drug storage

Answer 8

can be stored in

adipose tissue

bones

muscle - minimal

gallbladder and bile - small amount

Question 9

discuss hang over effect

Answer 9

is puno na plasma sedative will go to fat and once nagamit na sa plasma babalik sha from fat

hence effects will last even p 2-3 days

Question 10

properties of a pharmacologic active drug

Answer 10

lipophilic

unionized or partially ionized at physio pH

strongly bound to plasma proteins

Question 11

properties of a drug for renal excretion

Answer 11

hydrophilic

ionized or polar

unbound

Question 12

discuss biotransformation

Answer 12

enzymatic alteration of drug

parent drug = inactive form becomes active

Question 13

discuss phase 1 of metabolism

Answer 13

converts parent drug to polar metabolite

oxidation - reduction - oxidation reduction - hydrolysis

goes towards becoming hydrophilic

Question 14

discuss phase 2 of metabolism

Answer 14

partners c other substance to become polar conjugate

undergoes conjugation

some drugs rekta na phase 2

Question 15

discuss 1st order kinetics

Answer 15

percent or fraction of drug metabolized p time period

Question 16

discuss 0 order kinetics

Answer 16

mg of drug metabolized p time period

Question 17

significance of 1st and 0 order kinetics

Answer 17

can be 1st order or 0

or both; high dose 1st tpos 0 pag low

Question 18

major organs for metabolism

Answer 18

liver - main

lungs

kidneys

GI

skin

Question 19

discuss enzyme induction

Answer 19

ability of drugs to metabolize or inc acvtivity ng metabolites

hence in taking drug A and B ta s A is inducer

drug B effect will be less

Question 20

discuss enzyme inhibition

Answer 20

ability of drugs to inhib acvtivity ng metabolites

hence in taking drug A and B ta s A is inhibitor

drug B effect will more in effect

Question 21

organs for drug excretion

Answer 21

kidney - main

lungs

GIT

sweat

saliva

breast milk

bile

Question 22

discuss drug clearance

Answer 22

total rate of elimination in all organs

concentration inside - out/inside

Question 23

discuss half-life

Answer 23

t1/2

time where concentration at plasma is 50%

BY THIS TIME NEXT DOES NA DAPAT PARA STEADY STATE

Question 24

discuss dosing schedule and plasma concentration

Answer 24

maintain dose in plasma at therapeutic effect

above - toxic
below - no effect

dose = excreted

Question 25

discuss intermittent IV and cont infusion

Answer 25

intermittent - IV bolus, applied as neededh and maintains therapeutic range cont - more smoot

Question 26

discuss drug receptors

Answer 26

where drug binds to take effect fits only the shape of receptor

Question 27

discuss drug-receptor interaction

Answer 27

type specific law of mass action - inc dose of drug more binding kaya nag bibigay ng bolus

Question 28

discuss types of receptor binding

Answer 28

reversibel covalent - strongest ionic - electrostatic attraction hydrogen van der walls - weakest

Question 29

what is affinity

Answer 29

low - low attraction pag high edi mataas bet drug and receptor

Question 30

what are the 2 states a drug goes to upon binding

Answer 30

activated or inactivated

Question 31

drug classifications

Answer 31

agonist - classic effect upon binding antagonist/blocker - binds to receptor but no effect and blocks others from binding partial agonist - binds to receptor and gives lesser than real effect; for wanting to inc effect

Question 32

discuss types of antagonist

Answer 32

competitive - binds and can displace if dose is higher than drug non-compet - kahit taasan mo di ma ddisplace wait lang to be excreted

Question 33

what is receptor down regulation

Answer 33

dec concentration of receptors can be tolerance or insensitivity or tachyphylaxis - shorter duration ng drug effect

Question 34

discuss receptor up regualtion

Answer 34

inc sensitiyivy or supersensitivity ng receptos more toxic na sa usual dose

Question 35

variations that causes drug response and metabolism

Answer 35

genetics comorbidities diet