Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PHARM I > General Principals > Flashcards

General Principals Flashcards

1
Q

drug action

A

biochemical event

molecular mechanism,

not always known

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

drug effect

A

change in physiological function - such as increase contractility of the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the therapeutic window

A

it is the range b/w minimum effective concentration and toxicity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Local percutaneous administration
speed?
used for what?
examples?

A

used for derm conditions, SLOW sustained systemic absorption

Nicotine patch
scopolamine patch
nitroglycerin for angina

lipid soluble drugs–> penetrate much more easily than water soluble drugs

nasal sprays and eyedrops are other local routes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Enteral definition

A

via the GI tract

Sublingual
oral
rectal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

sublingual
speed?
advantages?
disadvantages?

A

warm, moist for RAPID dissolution

rich blood flow, close to mucosal surface

no first pass effect!

more rapid absorption than oral

unpleasant taste

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

oral

what are the barriers to absorption ?

A

most commonly used

the drug can either be absorbed by the stomach or intestine–> intestine is more significant!

barriers:

  • epithelial cells- tight junctions, must diffuse THROUGH these cells
  • capillary wall
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

why is the rate and extent of absorption in patients highly variable with PO drugs

A

gastric and intestinal ph
gastric emptying time
presence of food or none
other drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are the advantages and disadvantages of PO

A

A

  • convenient
  • safe- can use vomiting or lavage to remove the drug
  • inexpensive
D
slow- especially for water soluble drugs
variability
some are inactivated by the GI tract
first pass***
GI irritation 
requires conscious patient
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is the first pass metabolism

A

the liver inactivates a significant portion of many drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

parenteral definintion

A

non-oral route

IV
intra-arterial
Sub-Q
IM
Percutaneous
Inhalation
Intranasal
vaginal suppositories
intraocular 
epidural
intrathecal 
intraperitoneal
intra-articular
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

IV administration

A

no barriers
RAPID onset and control
NOT suitable for drugs that aren’t soluble
large volumes can be delivered

high cost
difficult access sometimes
inconvenient 
irreversible**
fluid overload
infection
embolism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is intra-arterial injection used for?

A

diagnostic procedures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

subcutaneous injection ?

uses?
timing?
examples?

A

lower blood flow so slower absorption
sustained action

drugs that are poorly soluble in water can be injected here

Depot preparations

most all protein drugs must be given this way

discomfort, potential for injury

example–> insulin or epi for emergencies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

IM injection

barrier?
time?
type of drugs used?

A

barrier is the capillary walls which are fenestrated so the drug gets in there with ease

time course dictated by –> water solubility of the drug and blood flow to the site of injection
highly soluble?–> absorbed rapidly (10-30 min)
poorly solube? longer time to absorb

generally there is high blood flow in muscle

allows oily or particulate matter, depot preparations, or drugs poorly absorbed or intolerable orally
example–> benzathine penicillin G - depot prep of penicillin

painful and inconvienient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

inhalation administration

A

localized to lungs so that there are less systemic effects
example- treatment of asthma with albuterol
or anesthetic agents

very large surface area for absorption

particle size important

17
Q

what happens to a drug that is used intranasally

A

lots of it is swallowed

18
Q

intrathecal?

A

CNS infections
pain
tumors

19
Q

how does lipid solubility of a drug effect its drug absorption

A

highly lipid soluble drugs are more readily absorbed than water soluble drugs

this is because lipid soluble drugs can cross the hydrophobic barrier of cell plasma membranes

20
Q

how does pH affect drug absorption

A

ionized drugs are charged
nonionized drugs are NOT charged

charged molecules CANNOT diffuse across the hydrophobic membrane barrier

21
Q

what drugs are located in the plasma compartment?

A

large drugs
extensively bound to plasma proteins
these can’t move through fenestrations of the capillaries

have a Vd of 4 L

22
Q

why might a drug only be able to be in plasma and extracellular fluids?

A

small enough to pass through endothelial fenestrations

BUT very hydrophilic and incapable of diffusing into cell

Vd is about 14 L in a 70 kg perosn

23
Q

what drug is able to diffuse into total body water

A

small enough and hydrophobic enough

Vd– may be 42 L in a 70 Kg person

24
Q

what is drug redistribution

A

a drug may be completely absorbed and distributed and then its concentration may fall below that of conc in tissues. then after that it may move back out of the tissue and into the blood along its concentration gradient

25
Q

what types of drugs penetrate the BBB

A

lipid soluble

26
Q

how are drugs eliminated from the body

A

urine, stool, sweat , breath

27
Q

what is biotransformation

A

enzymatic conversion of the parent drug into its metabolites

major site is the liver

28
Q

what is the elimination process in the …
hepatic and biliary secretions
renal elimination

A

hepatic and biliary: conjugation rxns which combine a sugar, amino acid or other residue making the drug larger and more water soluble

if the drug is too large to go through the kidney glomerulus then it is filtered in the bile

renal:
eliminated in the urine through glomerular filtration of the plasma

29
Q

what are 4 things that determine a drugs ability to passively diffuse?

A

lipid solubility
degree of ionization
-ionized molecules carry charge and favor interaction with water dipoles making them water soluble (Hydrophilic)

concentration gradient
molecular size of the drug

blood flow–> higher rate of flow maintains steeper concentration gradient

30
Q

what is the lipid/water partition coefficient

A

how soluble the drug is in water compared to oil…

the higher the more lipid soluble and the more likely the drug is to cross membranes

31
Q

excretion of weak acids out of the body is increase in ….. urine

A

basic urine

32
Q

excretion of weak bases out of the body is increased in ….. urine

A

acid urine

33
Q

how does pH affect plasma levels of a weak acid

A

if there is a weak acid in the plasma, its levels in plasma will FALL if the plasma is made more acidic . this is because if you add more acid (more H+ which is ionized) it will shift to a more non-ionized form and is then able to leave the plasma and enter tissues

34
Q

to promote a shift of an acidic drug out of the tissue into the urine, what can be induce therapeutically in the treatment of poisoning (such as phenobarbital poisoning)

A

alkalosis

35
Q

quaternary salts

A 
permanately charged
highly water soluble 
poorly absorbed 
won't readily cross BBB
rapidly excreted in urine if given IV
36
Q

which drugs are more likely to be plasma protein bound?

A

weak acids

lipid soluble drugs

37
Q

how does protein binding affect loading dose and other pharm decisions

A

binding sites may have to first be saturated with loading dose to achieve therapeutic concentrations

elimination half time may be prolonged if there is significant binding

glomerular filtration and renal excretion is affected b/c bound drug is not filtered

38
Q

drug interactions may result from what…

A

the displacement of drugs competing for binding sites

rapid IV administration favors displacement of drug from binding sites

drugs may displace endogenous substances such as thyroxine and result in toxicity

39
Q

thiopental versus pentobarbital. which one has the ability to “knock you out” and why

A

thiopental –> has a partition coefficient of 3.3 so able to reach CNS very rapidly

PHARM I (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions