Pharmacokinetics & Pharmacodynamics COPY Flashcards
1
Q
what are the four parts to the phamacokinetic phase?
A
- absorption
- distribution
- metabolism
- excretion
2
Q
What are the three parts to the pharmacodynamic phase?
A
- receptor binding
- postreceptor effects
- chemical reaction
3
Q
Drug movement from GI tract into bloodstream
A
drug absorption
4
Q
what does drug absorption require?
A
- -disintegration
- dissolution
5
Q
breakdown of oral drug form into small particles
A
disintegration
6
Q
process of combining small drug particles with liquid to form a solution
A
dissolution
7
Q
enteral
A
by mouth
8
Q
what are the different absorption methods?
A
- passive transport
- active transport
- pinocytosis
9
Q
most drugs are taken by this route
A
enteral
10
Q
resist disintegration in the gastric acid of the stomach, may be delayed in onset
A
EC Enteric Coated Drugs
11
Q
Where are EC drugs absorbed at?
A
small intestine
12
Q
what factors affect drug absorption?
A
- bloodflow, pain, stress, gastric pH
- food texture, fat content, temperature
- route of administration
13
Q
less blood flow =
A
less absorption
14
Q
shock, BP bottoms out =
A
decreased blood absorption
15
Q
which route of administration has the fastest onset of action?
A
IV
16
Q
Which route of administration is slower, dependent on blood flow area?
A
SubQ
17
Q
Which route of administration has a slow onset and is unpredictable?
A
Oral
18
Q
passive transport occurs through
A
- diffusion
- facilitated diffusion
19
Q
drugs move across the cell membrane from an area of higher concentration to lower concentration
A
diffusion
20
Q
relies on a carrier protein to move the drug from an area of higher concentration to lower
A
facilitated diffusion
21
Q
which transport does not require energy?
A
passive
22
Q
requires a carrier such as an enzyme or protein to move the drug against a concentration gradient
A
Active Transport
23
Q
energy is required for which transport?
A
active
24
Q
cell carries drug across membrane by engulfing drug particles
A
pinocytosis
25
after absorption of oral drugs from the GI tract, they pass from the intestinal lumen via what?
portal vein
26
what organ metabolizes drugs?
Liver
27
List drug movement in order starting with GI tract
- portal vein
- liver
- body
28
when the liver metabolizes a drug to an inactive form and is excreted, reducing the amount of active drug available to exert a pharmacologic effect
first pass affect or first pass metabolism
29
affected by the first past affect
bioavailability
30
% of administered medication that reaches systemic circulation (amount of drug actually available for use)
bioavailability
31
factors that affect bioavailability
- absorption
- first pass metabolism
- drug form
- route
- gastric mucosa and motility
- administration with food and other drugs
- changes in liver metabolism
32
decreasing liver function increases what?
bioavailability
33
movement of drug from circulation to body tissues
drug distribution
34
what are the influencing factors of drug distribution?
- protein binding
- free drugs
- blood brain barrier
35
as drugs are distributed in the plasma, many bind with
plasma proteins
36
list the different plasma proteins
- albumin
- lipoproteins
- Alpha-h acid-glycoprotein
37
what happens if a drug binds to protein?
it doesn't work
38
the portion of the drug bound to protein is inactive because
it is not able to interact with tissue receptors and is unable to exert a pharmacologic effect
39
portion of drug that is not bound to protein and is free
free drug
40
able to exit blood vessels and reach site of action causing a pharmacologic response
free drug
41
blood vessels of the brain made of special endothelial lining where the cells are pressed tightly together and protects the brain from foreign substances
blood brain barrier
42
what drugs are able to cross the blood brain barrier?
drugs that are highly lipid soluble and of low molecular weight such as benzo's
43
can drugs cross the placenta?
yes
44
drug metabolism is also known as
biotransformation
45
process of body chemically changing drug into form that can be excreted
drug metabolism
46
if the liver function is decreased, what happens to the drug effects?
increases
47
biologically inactive compound which is metabolized into the body and to produce a drug
prodrug
48
used to improve drug delivery, decrease toxicity or to target specific cells or tissues
prodrug
49
example of prodrug
codeine
50
why is codeine and example of a prodrug?
- little activation of opioid receptors as codeine
- metabolized into morphine by liver
- morphine activates opioid receptors
51
period of time required for concentration or amount of drug in body to be reduce by one-half
half life
52
affected by metabolism and elimination
half life
53
used to determine dosing interval
half life
54
decrease in liver and kidney function leads to an increase or decrease in half life?
increase
55
if you have a long half life, do you have to give a medication as often?
no
56
long half life leads to increase in
compliance
57
plateau drug level
steady state
58
steady state takes how many half lives?
4
59
large initial dose or series of doses to rapidly achieve therapeutic concentration and steady state
loading dose
60
example of loading dose
Z Pac
61
what are different ways that drugs are excreted?
- kidney
- liver
- lungs
- saliva, sweat, and breastmilk
62
what is the main route of drug excretion?
kidneys
63
how are drugs excreted from the liver?
through bile
64
how are drugs excreted through the lungs?
exhaled respiratory system
65
liver dysfunction leads to
decreased metabolism
66
kidney dysfunction leads to
decreased excretion
67
urine pH affects
excretion
68
acidic urine promotes elimination of
weak base drugs
69
alkaline urine promotes elimination of
weak acid drugs
70
which drug is excreted rapidly in alkaline urine?
salicylic acid (aspirin)
71
treatment of salicylate toxicity includes
IV admin of sodium bicarbonate
72
common tests to determine renal function
- creatinine
| - BUN
73
study of the way drugs affect the body
pharmacodynamics
74
desirable response
primary effect
75
desirable or undesirable response
secondary effect
76
primary effect morphine
pain relief
77
secondary effect of morphine
constipation (undesirable)
| diarrhea (desirable)
78
primary effect benedryl
treat allergy
79
secondary effect benedryl
```
sleep (undesirable)
bed time (desirable)
```
80
how much drug to get significant response
potency
81
no matter how much more you take of a medication it won't increase therapeutic effect
maximal efficacy
82
amount of med to give to produce effect
therapeutic dose
83
difference between potency and maximal efficacy
therapeutic index
84
ED50
therapeutic dose
85
give drug to 100 people and only half have a response to this. this is what type of dose?
therapeutic
86
give drug to the same 100 people and half show toxicity, this is what type of dose?
toxic
87
with narrow effect the nurse should monitor
drug toxicity and blood levels
88
what medications have a narrow effect?
- warfarin
- digoxin
- phenytoin
89
time it takes drug to reach minimum effective concentration
onset
90
highest concentration in blood
peak
91
small amount of drug necessary to get effect of drug
minimum effective concentration
92
length of time taken for a drug to exert therapeutic effect
duration
93
time to take next dose to keep wave going
term of action
94
measure taken after drug administration to monitor for toxic levels
peak drug level
95
measure before next dose, lowest drug level gets
trough
96
peak level of IV
30-60minutes
97
peak level of oral drug
3
98
receptor theory
drugs bind to receptors
99
drugs bind to receptors to inactivate a receptor by
blocking a response
100
activate receptors
agonists
101
prevent receptor activation
antagonists
102
block response
antagonist
103
affect multiple receptor sites
nonspecific drugs
104
affect multiple receptor types
nonselective drugs
105
decrease response to drug and need to increase dosage to get effect
tolerance
106
suddenly drug stops working after one or several doses
tachyphylaxis
107
predictable, not signs of toxicity
side effects
108
what is good for patient to know of drugs
side effects
109
undesirable effects, unexpected more severe, can occur at normal dosage
adverse reaction
110
drug level exceeds therapeutic range, too much of the drug and drug accumulation (liver or kidney dysfunction)
drug toxicity
111
highest risk in elderly, 1 in 5
drug interaction
112
when one drug affects another
drug interaction
113
what people are at risk for drug interactions?
- chronic health
- patient taking a lot of medication
- those taking different dietary supplements
- those who see more than 1 provider
- patient who use multiple pharmacies
114
changes occurring in absorption, distributions, metabolism, and excretion
phamacokinetic interactions
115
changes gastric pH
absorption
116
increase or decrease gastric emptying time
absorption
117
cause formation of drug complexes
absorption
118
induce production of hepatic enzymes
metabolism
119
metabolism can inhibit production of hepatic enzymes which means
drugs are metabolized slowly
120
what are impotent inhibitors that increase toxicity
- alcohol
- food
- grapefruit juice
121
diuretics cause what?
electrolyte imbalance
122
electrolyte imbalances cause what?
- decrease in cardiac output
- decrease of blood flow to kidneys
- decrease of excretion of other drugs
123
sum of effects of two drugs
additive
124
example of additive drugs
- hydralazine and nitro
| - both cause vasodilation and cause low BP
125
effect is much greater than affects of either drug alone
synergistic
126
example of synergistic
amoxicillin and coagulonate (antibiotics)
127
one drug reduces or blocks effects of other drug
antagonistic
128
example of antagonistic
- desirable nalaxone (narcan) (opioid overdose) blocks opioid receptor
- protamine sulfate (blocks heparin)
129
food may increase, decrease or delay drug response
drug nutrient interactions
130
drugs may cause misinterpretation of drug results
drug laboratory interaction
131
skin reaction caused by sunlight exposure
drug induced photosensitivity
132
cause BP to rise to dangerous levels
MAOI (monoamine oxidase inhibitor)
133
Is alcohol a drug?
yes
