Test 1: lecture 2-4

Question 1

name enteral routes of administration

Answer 1

oral
sublingual
rectal

Question 2

name some parenteral routes of admin

Answer 2

IV
IM
SQ

Question 3

what are some routes of administration not enteral or parenteral?

Answer 3

nasal
transdermal
interosseus
intraorbital
inhalation

Question 4

what are some routes that cause instant absorption

Answer 4

nasal
inhale
IV

Question 5

what enteral route of admin will avoid 1st pass

Answer 5

sublingual
rectal

1st pass: ↑% of drug broken down in liver before it is distributed in the body

Question 6

what is pKa

Answer 6

pH that the concentration the uncharged and charged are equal

if pKa is 4.4 and pH 4.4 → equal

if pH 3.4 (more acidic) there will be more uncharged then charged

Δ in pKa by 1= x10 change

Question 7

if pkA is 4.4 at what pH will uncharged and charged be equal

Answer 7

4.4

Question 8

if pKa = 4.4 and pH 3.4 what will happen

Answer 8

lower pH = more acid/H available

there will be a 10x increase in the non charged molecule

Question 9

In general, weak acids will be better absorbed from — compartments while weak bases will be better absorbed from — compartments.

Answer 9

acidic

alkaline

Question 10

fraction of % of drug that enters ciculation after 1st pass effect

Answer 10

bioavailability

if 10 mg PO, 40% absorbed, 75% by 1st pass effect

Bioavilability= 10x0.4= 4 mg to liver
4- (4x0.75)= 1 mg

Question 11

what is bioavilability of IV?

Answer 11

100%

Question 12

if 10 mg PO, 40% absorbed, 75% by 1st pass effect

what is bioavailability?

Answer 12

10x0.4= 4 mg to liver
4 - (4x0.75)= 1 mg

1 mg out of 10 mg= 10% or 0.1

Question 13

weak bases tend to be absorbed from the —

Answer 13

intestine (where pH is more basic >7)

Question 14

hypothetical volume of plasma into which a drug distributes after bistribution

Answer 14

volume of distribution

Question 15

how to calculate volume of distribution

Answer 15

(bioavailable dose) ➗ (concentration of drug in plasma after distribution)

Question 16

is pKa= 4.4 how much of either side

Answer 16

top: 7.4-4.4= 3
↑pH= less H = A-
10^3 x 1= 1000
1+1000= 1001

bottom 3 below pKa= 10^(-3) x 1= 0.001
1+0.001= 1.001

total= 1002.1

Question 17

what will happen?

Answer 17

Question 18

weak — will tend to acumulate in an acidic compartment

Answer 18

base

Question 19

weak — will tend to accumulate in basic compartment

Answer 19

acid

Question 20

how many L of water per kg of weight?

how many L for a 70kg person?

Answer 20

0.6 L/kg

70 kg person would have 42 L of water space

Question 21

if Volume of distribution is greater then plasma in a person then —

Answer 21

drug is accumulating in body outside plasma

if Vd=100L/kg
there is only 0.6L/kg of plasma in a person
volume has moved out of plasma.

Question 22

if Vd= 0.1L/kg what does that mean

Answer 22

plasma in body = 0.6L/kg

smaller= all the drug is distributed inside the plasma

Question 23

to get theraputic concentration of 0.1mg/L
1 kg patient, Vd=100 L/kg

how much drug to give?

Answer 23

100 (L/kg) x 0.1 (mg/L) x 1 kg = 10 mg

Question 24

time required to metabolize 50% of drug

Answer 24

half life
T1/2

Question 25

half life 6 hrs, how much is eliminated in 24 hrs?

Answer 25

Question 26

— is the ability of the body to eliminate a drug by all routes

Answer 26

clearance

Question 27

explain

Answer 27

ex: anesthesia
drug will first be very high in brain (central compartment)

then will redistribute into other fatty areas (legs)

this is why you will wake up quickly, but can’t drive, drug has moved comparments but has not been eliminated yet

Question 28

Answer 28

Question 29

1st order vs 0 order kinetics

Answer 29

1st order: same fraction of drug is elimiintaed in any given time interval, eventually will get to peak and through dosage that is stable

zero order (alcohol): enzymes are saturated): the same amount of drug is eliminated in any given time period → build up of drug in the system (can’t excrete fast enough)

Question 30

how does zero order kinetics work

Answer 30

alcohol): enzymes are saturated): the same amount of drug is eliminated in any given time period → build up of drug in the system (can’t excrete fast enough)

Question 31

why no asprin in cats

Answer 31

low glucuronide synthesis

(takes much longer to degrade Asprin)

Question 32

how does Vd change in neonate

Answer 32

have more fat= more distribution

enzymes have not formed all the way= different distribution