AMDE Flashcards
(75 cards)
1
Q
How a drug moves from its site of
administration into the bloodstream
A
Absorption
2
Q
Movement of the drug between blood and
tissues
A
Distribution
3
Q
Conversion of drugs into more hydrophilic
metabolites
A
Metabolism
4
Q
Removal of drugs and/or metabolites from
the body
A
Excretion
5
Q
Where does the majority of the absorption into blood stream from GI tract occur?
A
Small intestine
6
Q
If the molecule is larger, it will absorb more or less?
A
Less movement
7
Q
Do ionized or non-ionized molecules move better?
A
Non-ionized
8
Q
Does increased lipid solubility increase or decrease movement?
A
Increase movement
9
Q
Does increased protein binding increase or decrease movement/
A
Decreases movement
10
Q
To pass through lipid membranes, drugs
have to be ________
A
non-ionized (aka: uncharged)
11
Q
To be water soluble, drugs need to be
_________
A
ionized (aka: charged)
12
Q
Most drugs are either ____ acids or _____ bases
A
Weak acids or weak bases
13
Q
What is the protonation and ionization of an acid drug in an acidic ph?
A
non-ionized; protonated
14
Q
What is the protonation and ionization of an acid drug in an basic ph?
A
Ionized, deprotonated
15
Q
What is the protonation and ionization of an basic drug in an acidic ph?
A
Ionized, protonated
16
Q
What is the protonation and ionization of an basic drug in an basic ph?
A
Non-ionized; deprotonated
17
Q
_____ are non-ionized (fat soluble)
when protonated, ionized (water soluble) when
deprotonated
A
Acids
18
Q
_____ are non-ionized when deprotonated,
ionized when protonated
A
Bases
19
Q
The ___ is the pH at which there are
equal amounts of protonated and
nonprotonated
A
pKa
20
Q
pH __ pKa Protonated equals non-
protonated
A
pH=pKa
21
Q
pH __ pKa Protonated form predominates
A
pH < pKa
22
Q
pH ___ pKa Non-protonated form predominates
A
pH > pKa
23
Q
Only the ________ form of a drug can
readily cross the lipid membrane
A
non-ionized
24
Q
Ion Trapping Because ionized molecules (drugs) can’t cross the membrane, can effectively trap them and enhance excretion Principle is very useful in toxicology cases
A
Ion Trapping
25
Typically the ____ form of the drug is lipid soluble meaning it readily absorbs into bloodstream
Non-ionized
26
Will a more acidic or basic local anesthetic get absorbed in an abcess better?
Acidic
27
According to Fick's law, what 2 things are proportional to the rate of absorption?
Concentration of drug
| Surface Area
28
Movement of a drug from its site of administration into the central compartment
Process of dissolution and diffusion
Bioavailability more important
Absorption
29
Fraction of drug that reaches the systemic
circulation intact
IV = 100%
Affected by route of administration
Bioavailability (F)
30
Fraction of drug in blood that is irreversibly
| removed during one pass through the liver
Hepatic extraction ratio
31
Extent to which a drug is removed by the liver
during its first pass in the portal blood through
the liver to systemic circulation
First pass clearance
32
Drugs with low hepatic extraction will have
| ___ first pass clearance
low first pass clearance
33
```
____ extraction
Low first pass
clearance
Change in hepatic
enzymes won’t have
significant effect on
first pass clearance
- Increased drug in bloodstream
```
Low extraction
34
```
_____ extraction
High first pass
clearance
Changes in enzyme
function will have large
effect on first pass
effect
- Decreased drug in bloodstream
```
High extraction
35
_____ route of administration:
| Hits digestive system before going to bloodstream
Enteral
36
_____ route of administration:
| -Bypasses digestive tract: Decreases first pass effect
Parenteral route
37
```
_____ administration
ADVANTAGES
Most common route
Safest
Easiest
Most economical
DISADVANTAGES
Limited absorption
Emetogenic potential
Subject to first pass
Absorption may be
affected by food or other
drugs
Irregularities in
absorption or propulsion
```
Enteral administration
38
```
______ Administration
ADVANTAGES
Not subject to first pass
Most rapid onset
Ability to titrate
Doesn’t require cooperation
DISADVANTAGES
Greater patient discomfort
Requires additional training
to administer
Concern for bacterial
contamination
Injection-associated risks
Extravasation
Intra-arterial injection
Limb loss
```
Parenteral Administration
39
```
_____ Administration
Absorption governed by:
Surface area for absorption
Blood flow to site of absorption
Dosage form administered
Ionization status (lipo- vs. hydrophilic)
Concentration at site of absorption
```
Oral Administration
40
```
Drugs destroyed by
gastric secretions, low
pH, or that cause
gastric irritation
Risk of bezoar
formation
Delayed Release
```
Enteric coating
41
F = 100%● Immediate onset, Bypasses GI absorption
| ● Best for emergencies
►Intravenous (IV):
42
75-100%● Irritating drugs given this route
● Not as rapid response as IV
● Depot preparations (sustained release) ie., suspensions, ethylene glycol,
peanut oil- all slow down absorption.
►Intramuscular (IM):
43
: 75-100%● Slower absorption than IV or IM
● Little risk of intravascular injection
● Examples: Insulin, Mechanical pumps, heparin (DVT prophylaxis)
►Subcutaneous (SQ)
44
:● Small amounts of drug
| ● Tuberculosis skin test, Local anesthetics
► Intradermal (ID)
45
5-100%● Almost as rapid as IV. (Method of abuse)● Delivered directly to lung (good selectivity)- minimal systemic side-effects.
● Gases, aerosols of solutions & powders -good for respiratory conditions.
► Inhalation:
46
: 5-100%● Vasopressin for tx of diabetes insipidus, calcitonin (osteoporosis).
● Method of drug abuse.
► Intranasal
47
● Subarachnoid space of spinal cord – into CSF (Lumbar puncture- Baclofen
in MS, regional anesthetic in delivery, morphine drip)
Intrathecal/Epidural:
48
Skin, oral mucosa, sublingual, rectal (avoids 50% of 1st pass metab)
● When local effect is desired-but can provide systemic effects.
● Sublingual (100%), rectal (50%) bypasses liver- good bioavailability.
● Transdermal Controlled Release- Scopolamine, nitroglycerin, nicotine,
estrogens (BCP), fentanyl.
Topical:
49
Perio specific uses: doxycycline(Atridox); minocycline(Arestin)
Subgingival:
50
```
The administered drug leaves the blood
stream and enters other “compartments”
Dependent upon:
Cardiac output
Capillary permeability
Blood flow
```
Distribution
51
What are the 3 things that distribution is dependent on?
Cardiac output
Capillary permeability
Blood flow
52
The the heart, liver, kidney, adipose tissue, and brain; rank the amount of blood flow from most to least?
```
Kidney
Liver
Heart
Brain
Adipose tissue
```
53
____ compartment
| Well perfused organs and tissues (heart, blood, liver, brain, kidney). Drug equilibrates rapidly.
Central
54
_____ compartment
| Less well perfused organs/tissues (adipose, skeletal muscle, etc.)
Peripheral
55
______ compartments
| CSF, CNS, pericardial fluid, bronchial secretions, middle ear
Special compartments
56
What protein binds acidic drugs?
Albumin
57
What protein binds basic drugs?
Alpha-glycoprotein
58
Distribution of a drug that moves From site of action into other
tissues or sites
Redistribution
59
```
Lipid solubility
Clinical effects
Efflux transporters
Inflammatory
processes
```
Blood brain barrier
60
```
Volume of fluid in which a drug would
need to be dissolved to have the same
concentration in plasma. Doesn’t
represent “real” volume
Relationship between dose and resulting
Cp
```
Volume of Distribution (Vd)
61
Lipophilic drugs tend to have a ___ Vd
larger
62
Protein bound drugs have ____ Vd
lower
63
```
Removal
Either metabolized/biotransformed and
eliminated or excreted unchanged
Must be water-soluble to be removed
Lipid solubility good for absorption and
distribution, bad for excretion
Process of biotransformation
Converts drugs into polar metabolites
Lipophilic into hydrophilic
Liver does the heavy lifting
P-450
```
Metabolized
64
What organ does the majority of metabolism?
Liver
65
What cytochrome system does the majority of metabolism in liver, kidneys, and intestines?
P-450
66
Phase ___ of metabolism
Catabolic
Exposes functional group on parent compound
Usually results in loss of pharmacologic activity
Activation of prodrugs
Phase 1
67
IF there is a drug inhibitor that inhibits drug binding to enzyme, is there an increased or decreased drug response?
Increased drug response
68
IF there is a drug inducer that induces drug binding to enzyme, is there an increased or decreased drug response?
Decreases drug response
69
```
Phase ___ of metabolism
Occurs after functional groups are exposed
Anabolic: adds water soluble molecules to
structure
Much less interpatient variability
Major reactions
Glucuronidation
Glutathione conjugation
Sulfate conjugation
Acetylation
```
Phase II
70
Removal of unchanged drug
Kidney, lung, feces – primary routes
Polar compounds > lipid soluble
compounds
Excretion
71
During excretion, is the lipid or water soluble more prevalent?
Water soluble
72
```
3 processes
Glomerular filtration
Active tubular secretion
Passive tubular reabsorption
Dependent upon renal function Only unbound drug filtered Non-ionized weak acids and bases passively reabsorbed Alkaline urine “traps” ionized, acidic molecules, increases excretion
```
Excretion
73
Unabsorbed orally administered meds; the metabolites are excreted in the ____
Bile
74
_______ is main factor that determines rate of passive transport
Lipid solubility
75
Only _____ drugs can diffuse across lipid membrane
uncharged
