nurs 116 lecture 2

studied byStudied by 14 people
5.0(1)
Get a hint
Hint

where are most po drugs absorbed?

1 / 78

flashcard set

Earn XP

Description and Tags

stopped at half-life

79 Terms

1

where are most po drugs absorbed?

>90% absorbed by villi in sm int (duodenum, jejenum)

New cards
2

GI mucosa absorption drugs to known

amy ate caffeine with pie

alcohol

aspirin (ASA)

caffeine

warfarin (coumadin)

phenytoin (dilatin)

New cards
3

what is distribution?

transportation of drug to target tissue

New cards
4

factors affecting distribution

  1. *blood flow to the tissue (ex. CO, BBB, injury)

  2. size of tissue

  3. molecular characteristics (lipohilicity, size, ionization)

  4. PPB

New cards
5

% of blood flow to organs at rest from most to least

  1. liver (25%)

  2. kidney/muscles (20%)

  3. brain (18%)

  4. skin (7%)

  5. bone marrow/heart (5%)

New cards
6

what allows for selective transport of substances through BBB?

p-glycoprotein pump

New cards
7

where is the exception of the BBB?

the hypothalamus. it is needed to relay info about toxicity to chemoreceptors

New cards
8

structure of BBB

endothelial cell —> basement membrane —> astrocytes with tight junctions

New cards
9

what binds to albumins?

acidic drugs like ASA

New cards
10

what binds to alpha-1-acid glycoprotein

basic drugs

New cards
11

what does PPB do to distribution?

decreases it

New cards
12

characteristics of PPB

competitive, reversible, saturable

New cards
13

unbound vs. bound drugs

unbound = effective

bound = not effective

New cards
14

drugs extensively bound (>90) - worthless imps need fat dumplings

warfarin

ibuprofen

naproxen

furosemide

digitoxin

New cards
15

volume of distribution (vd)

estimates how extensively a drug is distributed into tissue

-assumes total drug equally reaches tissue

-relative comparison ONLY

New cards
16

vd calculation

drug dose/plasma concentration

New cards
17

metabolism/biotransformation

an enzymatic chemical conversion to prepare the drug/substance for excretion

New cards
18

what does biotransformation cause?

termination of drug action

New cards
19

what are other metabolizing organs?

lungs, kidneys, mouth (saliva)

New cards
20

what does the liver contain for biotransformation?

hepatic microsomal enzymes

-P450 system

New cards
21

types of biotransformation metabolization

  1. active drug to inactive metabolite

  2. active drug to active metabolite

  3. inactive drug to active metabolite (prodrug)

New cards
22

example of prodrug

codeine —> morphine

New cards
23

T or F: kids can have codeine

F

New cards
24

phase 1 metabolism

-hydrolysis, reduction, oxidation

-remove hydrogen and add oxygen (polar metabolite)

-CYP450 enzyme group

New cards
25

main CYP450 enzyme groups

  1. CYP3A4/5 - 50% of drugs use

  2. CYP2D6

  3. CYP2C8/9

  4. CYP1A2

New cards
26

what metabolized acetaminophen?

CYP 3A4/1A2

New cards
27

CYP 3A4/1A2 inducer vs. inhibitor for acetaminophen

inducer: tobacco

inhibitor: some antibiotics

New cards
28

phase 2 metabolism

-conjugation (side chain addition) and polarization

New cards
29

acetaminophen phase 2 metabolism

acetaminophen —> phase 1 —> n-acetyl-p-benzo (NAPB) —> hepatoxic —> phase 2 —> glutathione enzyme conjugation —> inactive metabolite

New cards
30

consequence of tylenol overdose

depletes glutathione which lets the hepatoxic metabolite to build up in the tissue

New cards
31

what is the primary organ of excretion?

kidney

New cards
32

other excretory pathways

saliva, bile, lungs

New cards
33

biliary excretion pathway

drugs —> bile —> duodenum —> lg int —> feces

New cards
34

what % of unchanged drugs does the kidney excrete?

30%

New cards
35

general pathway of kidney excretion

afferent —> glom capsule —> efferent

New cards
36

ideal molecular characteristics for renal excretion?

ionization, hydrophilicity, small size

New cards
37

excretion + PPB?

not excreted

New cards
38

excretion + metabolisation?

excreted only if metabolized/unchanged throughout

New cards
39

excretion + urinary pH?

pH of filtrate is changed for excretion

acid in alkaline filtrate (vice versa)

ionized —> secreted —> excreted

New cards
40

example of urinary pH being changed for excretion?

ASA (acidic) + NaCO3 admin to pt = ionized —> excrete

New cards
41

factors affecting renal excretion

molecular characteristics, cardiac output, renal function

New cards
42

what is normal GFR function

125 mL/min

New cards
43

write out the cockcroft-gault formula for estimating creatinine clearance

CrCL (ml/min) = (((140-age) x lean body weight (kg))/(serum creatinine (mg/dL) x 72)) x (0.85 if female)

New cards
44

what is clearance (cl)

rate of elimination of drug in an hour

New cards
45

1st order elimination kinetics

most drugs, readily metabolized in the liver

elimination proportionate to the drug serum (mg/dL or L)

New cards
46

how is Cl calculated (1st order)

elimination/peak plasma concentration (mg/dL/hr)

New cards
47

zero order elimination kinetics

rate of elimination is constant

New cards
48

zero order drugs

every ass poops

-etoh

-aspirin (ASA)

-phenytoin (dilantin)

New cards
49

what is half-life

time required for cmax drug plasma concentration to decrease by 50%

New cards
50

T or F: if a drug has a long half-life, it takes a short time to be excreted

F

New cards
51

why is half-life important?

guidelines for frequency of drug administration

New cards
52

how long does it take for a drug to be >90% cleared?

4 x halflife

New cards
53

zero order kinetics saturable drug examples

alcohol

aspirin, phenytoin (in excess)

New cards
54

drug-receptor binding factors

saturable

increases or suppresses existing processes

blocks the receptor

New cards
55

recepter affinity

strength/length of binding

specific, saturable, reversible

New cards
56

what type of drugs perform a necessary action, but negatively affect the cell?

cytotoxic drugs that kill cells for cancer tx

New cards
57

do antagonists have efficacy?

most don’t. they only block receptors

New cards
58

drug A is 20mg and drug B is 10mg. which one is more potent?

drug B

New cards
59

what is an agonist

mimics an endogenous substance

binds readily for very good effects

New cards
60

what does morphine mimic?

endorphins

New cards
61

primary agonist

extensively & successfully binds to existing receptor

New cards
62

partial agonist

maximum response is smaller even if all receptors occupied

lower efficacy

New cards
63

what’s the issue with using a partial agonist?

in the presence of a full agonist, it acts as an antagonist

New cards
64

what does buprenorphine act as an antagonist to?

morphine b/c they go for the same receptors

New cards
65

inverse agonists

induce opposite effect of the naturally binding substance

New cards
66

caffeine properties

inverse agonist

mostly hydrophilic, lipophilic enough to have an effect

does not bind to alpha/beta receptors

New cards
67

what receptors does caffeine bind to for an inverse effect?

adenosine receptors, which are used for a calming effect

New cards
68

what type of -gonist is naxalone?

antagonist. stronger affinity to opioid receptors, so it knocks it off for a short time to reverse OD

New cards
69

6 major types of receptors

g-protein (GPCR)

ion channels

nuclear receptors

intracellular enzymes

transmembrane enzymes

non-enzyme (JAK-STAT)

New cards
70

majority of ion channels that drugs bind to?

voltage gated channels

New cards
71

lidocaine

closed ion channels that prevent pain transfer

New cards
72

nuclear receptors

aka steroid receptors

most bind in cytoplasm = change cell fx via DNA

New cards
73

example of nuclear receptor ligand

hormones

New cards
74

example of enzyme binding (insulin)

insulin binds to cell membrane receptors to stim transmembrane enzyme tyrosine kinase —> activate cellular glucose uptake

New cards
75

JAK-STAT receptors used by what?

interferons

New cards
76

drug tolerance

aka down regulation: receptor de-sensitization or decreased number of viable receptors

most common

New cards
77

drug resistance

drug is less effective bc of PK changes

ex. increased drug metabolism —> less bioavailable —> less effective

New cards
78

T or F: drug resistance = antibiotic resistance

NO

New cards
79

antibiotic resistance

bacteria acquires resistance

New cards

Explore top notes

note Note
studied byStudied by 11 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 8 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 82 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 14 people
Updated ... ago
4.5 Stars(2)
note Note
studied byStudied by 9 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 22 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 8 people
Updated ... ago
5.0 Stars(1)
note Note
studied byStudied by 118 people
Updated ... ago
5.0 Stars(1)

Explore top flashcards

flashcards Flashcard30 terms
studied byStudied by 31 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard61 terms
studied byStudied by 3 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard20 terms
studied byStudied by 6 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard20 terms
studied byStudied by 20 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard83 terms
studied byStudied by 3 people
Updated ... ago
5.0 Stars(1)
flashcards Flashcard55 terms
studied byStudied by 95 people
Updated ... ago
5.0 Stars(2)
flashcards Flashcard57 terms
studied byStudied by 16 people
Updated ... ago
5.0 Stars(2)
flashcards Flashcard120 terms
studied byStudied by 44 people
Updated ... ago
5.0 Stars(1)