Pharmacokinetics + Pharmacodynamics Flashcards
Midterm 1 Review
1
Q
What is pharmacology?
A
Science of the fate of drugs in the body and their biological actions within the body.
2
Q
Primary drug action
A
Therapeutic effect
-Usually intended to be beneficial
3
Q
Secondary drug action
A
Side effects
-can be desirable, undesirable, or neutrla
-If unwanted side effects occur; usually called adverse reactions
4
Q
Who regulates drugs?
A
The Food and Drugs Act (FDA)
5
Q
Branches of the FDA
A
Natural health products
Biological
Pharmaceutical
Food
^(Above 3 are all under the Food and Drug Regulations)
Cosmetics
Devices
6
Q
3 main uses for drugs?
A
- the Dx, Tx and prevention or diseases or it’s Sx’s
2.Restoring/correcting organic functions
3.Disinfection in places where food is
7
Q
What kind of effect do drugs give?
A
Local or systemic
8
Q
Device
A
Aimed at the functioning of a body part
9
Q
What is considered to be a drug?
A
Pharmaceutical, biologics (biologically-derived products), disinfectants, natural health products
10
Q
Pharmaceuticals can be either…?
A
Prescription or non-prescription
11
Q
Biologics come from…?
A
Living organisms or their cells
-Often made using biotechnology
12
Q
Biologics include…
A
-Blood and blood products
-Viral +bacterial vaccines
-Cells, tissues, organs
-Antibodies
-Gene therapies
13
Q
What are biologics used for?
A
To treat disease and medical conditions like;
-Anemia
-Diabetes
-Psoriasis
-Rheumatoid arthritis
-Inflammatory bowel disease (IBD)
-Hormone deficiency
-Some forms of cancer
14
Q
Natural health products include…
A
Vitamin and mineral supplements
-Therapeutic claims made
15
Q
Pharmacology started out as…
A
Potions, elixers, herbal remedies and evolved through centuries of trial and error
16
Q
Botanists
A
Screen natural materials
17
Q
Chemists
A
Extract and purify these natural materials (ex. morphine from opium) so that the active ingredient could be synthesized
18
Q
Sources of drugs
A
1.Natural preparations (Ex. Opium)
2.Purified components (Ex. Morphine)
3.Derivatives of natural products (Ex. Heroin)
4.Totally synthesized compounds (Ex. Fentanyl)
19
Q
3 main drug nomenclatures
A
- Chemical name (Ex. Ortho-acetoxybenzoic acid)
- Generic name (international nonproprietary name) (INN) (Ex. Acetyl salicylic acid - ASA)
- Brand/Trade name (Ex. Aspirin)
20
Q
Innovator Drugs
A
Also = Brand name drug
-Patent protected for 20 years, once expired any other pharmaceutical company can market the drug without the same brand name
21
Q
Generic drug (not to be confused with generic name)
A
Also called subsequent entry drug
-Contains the same active ingredients as the original brand name drug approved for sale
-Often sold under a name that incorporates the generic name (often with an added prefix representing the company)
22
Q
For biological products, generic drugs (subsequent entry drugs) are also called…?
A
-Biosimilar products
23
Q
Does everything we eat flow through the liver? T/F?
A
True
24
Q
The Liver can’t tell the difference between good and bad chemicals so it will breakdown it all (sometimes inactivating medications we take) T/F?
A
True
25
What happens when a drug enters the body? (Acetaminophen tablet PO)
1.Once the drug goes into solution it is absorbed from the digestive tract into systemic circulation
2.Reversible binding to plasma proteins and circulation/distribution in the body
3.Most drugs bind to specific receptors
4.Transformation/metabolism (by liver)
5.Kidney's, lungs, intestines can eliminate drug
^The above process influences the speed of onset and duration of drug effects
26
Metabolites
Substance produced when the body (likely the liver) breaks down a drug
-Can be Active or Inactive
27
What does Albumin (the mist abundant plasma protein in the body) do?
Helps fluid from leaking out of your blood vessels (capillaries) into other tissues
28
29
Where is bile released into?
The duodenum
30
How do most drugs work?
By binding to receptors
31
Drugs are absorbed through which intake routes...?
Oral intake, inhalation, injection
32
Distribution of drugs takes place in the...?
Blood vessels (circulation) attach receptors
33
Drug transformation happens where?
the liver is the site of biotransformation (some other sites not listed)
34
Elimination of drugs happens by which routes?
feces, exhalation, urine, sweat, saliva
35
Pharmacokinetics
Study of factors determining the concentration of a drug at the receptor site, as a function of time and dose administered
ADME (absorption, distribution, metabolism, excretion)
36
Pharmacodynamics
Study of the biochemical and physiological mechanisms by which drugs produce their effects (Includes mechanism of action)
37
Pharmacokinetics vs. pharmacodynamics
Pharmacokinetics: What the body does to the drug
Pharmacodynamics: What the drug does to the body
38
A-Absorption Routes of administration
IV
IM
SC
PO
PR
IA
SL (Sublingual - under the tongue)
Inhalation
Topical
Transdermal
Vaginal
Opthalmic
39
Intravascular vs. extravascular
Intravascular doesn't require any absorption
Extravascular route requires absorption
40
Intravascular routes
Intravenous
Intra-arterial
41
Extravascular routes
Oral, rectal, IM, SC
42
Transdermal route means?
In the nose (Ex. Spray)
43
Inhalation meaning?
Being pushed right into the lungs, not the nose, (Ex. Inhaler)
44
Enteral (gastrointestinal) routes of administration
-Under the tongue (PO, SL - don't swallow)
-Pr
45
Parenteral (Injection) routes of administration
SC
IM
IV
IA
46
A.C
Before meals
47
ad lib.
As much as desired; freely (rarely used for meds. mainly for food - different than prn)
48
B.I.D
Twice a day
49
H.S, QHS
H.S= At bedtime
QHS= Every bedtime
50
P.C
After meals
51
P.V
Vaginally
52
q
Every; per
53
q.d
Every day
54
q.i.d
4 times a day
55
t.i.d
Three times a day
56
Applying drugs on a surface - Topical administration
-Direct application to where it must act
Ex. skin creams, ointments, nasal sprays (inhalation is different), vaginal applications, eye drops
57
Simplest mode of administration=
Topical
58
Ointment vs. cream
Ointment is more oily (ex. vaseline, polysporne)
-Still glistens on the skin after rubbed in
-Stays on the surface of the skin mainly - that's what you want an ointment for
Cream is when you rub it in and it disappears (sinks into the skin)
59
Applying drugs on a surface - Transdermal administration
-Is a patch you put on your skin
-Gradual absorption through intact skin; variable absorption (proportional to lipid solubility, blood flow)
-Often can be a route for poisoning (ex. insecticides)
-Ex. Hormone treatment, nicotine, fentanyl, nitroglycerin
60
Administration by inhalation
-Rapid access to general circulation via the lungs
-Ex. anesthesia for surgery, bronchodilators for asthma (salbutamol)
61
Perfusion
-When you give the med. drop by drop
62
Enteral (gastrointestinal) - Oral P.O
-Most common route of administration
-Exposure to intestinal and liver metabolism before gaining access to systemic circulation
-Absorbed like nutrients and travel through the liver before gaining access to systemic circulation
63
Oral - Tablets/capsules
-Active ingredient + excipients (Inactive ingredients) (ex. starch, color, preservatives, coating)
-Take with sufficient liquid (100mL)
-Some should not be split or crushed (enteric-coated, slow/extended release, gelatin capsules)
64
Why are some pills coated?
To protect the stomach from the pill or to protect the pill from the acid of the stomach
65
Woul a drug that is highly destroyed by the liver be taken by mouth (P.O)?
No. (Ex. nitroglycerin never taken P.O, taken s.l instead)
66
Oral - Liquids (3 types)
Emulsions: mix of water/oil
Suspensions: Insoluble matter in water, mix well before dispensing (ex. sand in water)
Tincture/elixir: Alcohol-based (used to extract active components from plants)
67
Hepatic portal system route taken
1. Small intestine absorbs products of digestion
2.Nutrient molecules travel in hepatic portal vein to liver
3.Liver monitors blood content
4.Blood enters general circulaton by way of hepatic vein
68
How the sublingual route works
Gets drained from under the tongue by veins in the neck to the superior vena cava (of the heart) good for pills that act directly on the heart
69
Veins into and back out of the liver
Hepatic portal vein into the liver and hepatic vein out of the liver
70
Enteral (gastrointestinal) routes of administration - Sublingual
-Absorption through the oral mucosa
-The point of it is to avoid the liver
-Bypasses first-pass liver metabolism
Ex. nitroglycerin used for the Tx of angina
71
Bucco-gingival
-Drug dissolves between gums and cheek
72
Enteral routes of administration - Rectal (p.r)
-Useful in cases of nausea, vomiting or local issues
Ex. anti-inflammatory drugs for hemorrhoids
73
First pass metabolism
Enzymatic activity that can transform a drug in the way IN
Ex. can have elevated first pass metabolism
-Can be first pass liver, intestinal, pulmonary, hepatic metabolism
74
I.v injection, common example
Adrenaline/epinephrine (same thing)
75
I.m injection, common example
Diazepam
76
S.c injection, example
Insulin
77
Intravenous administration
-Most direct route
-Requires extra vigilance (esp. in 1st hour after administration)
78
Why is the intravenous route risky?
-High concentrations = increased risk of toxicity
-Risk of injection site infection
-Phlebitis: Caused by hypertonic solution or direct effect of drug
-Accidental extravascular administration (go through the blood vessel to the other side into surrounding tissue)
-Air embolism
79
Intra-arterial perfusion
-Used for some chemotherapeutics
-Lysis of blood clots
80
Parenteral administration via central venous catheter (PICC line)
Point is to get access to major blood supply carries
81
Intraosseous administration
The bone marrow cavity (ex. tibia, humerus, sternum) is used as a non-collapsible vascular entry point
-Used in resuscitation of critically ill adult patients if rapid and timely peripheral intravenous cannot be established or has failed
82
Possible complications of intraosseus administration?
Extravasation, infection and fracture
83
What is concentration the relationship of?
Concentration is the relationship between quantity and volume
84
Therapeutic range
Anywhere above the threshold
-Where you feel the effects
85
Why does drug concentration in the blood drop?
Because of metabolism
86
T-max
The time required for the drug to get to the maximum concentration in the blood
87
Threshold
The onset of action can begin to occur at the threshold (lowest amount of the drug in the blood to feel effects start)
88
Phlebitis
Inflammation of a vein near the skin of the surface
89
4 principles of bioavailability
Absorption - bioavailability
Distribution - volume of distribution
Metabolism - Half-life
Elimination - Clearance
90
Bioavailability F =
The fraction of unchanged drug (unmodified and still active) that reaches the systemic circulation
91
What is ideal bioavailability?
100% (no losses between site of administration and systemic circulation)
92
F < 100% can mean...?
-Some of the drug is lost before reaching the heart
-Lost before intestinal absorption (ex. diarrhea)
-Lost by modification of the drug by intestinal or hepatic metabolism (enzymes)
-Lost because transporters return the drug to the gastrointestinal tract (into bile, small intestines)
93
Systemic circulation means?
The blood that's leaving the heart to fill the body
94
If a drug has an elevated first pass metabolism, does it have increased or decreased bioavailability?
Decreased because (ex. 90% destroyed by the liver, 10% not) then drug has been changed a lot and not much left to distribute
95
Is bioavailability on the way in or out?
IN!!!!!!!!!!!!!
96
Oral availability is 50% compared to IV route T/F?
True
97
How is bioavailability calculated?
AUC Proportional dose x F/clearance
-By comparing the amount of drug absorbed over time from the route of administration of interest to the amount of drug absorbed over time when the same dose is given by intravenous route
98
AUC (Area under the curve) is directly proportional to the clearance of the drug T/F?
False
99
The larger the dose of the drug the smaller the area under the curve T/F?
False
100
If clearance is high, drug concentration will be lower in the body T/F?
True, because high clearance means normally functioning kidney's and liver so drug concentrations in the body will be lower because the drug is eliminated by the kidney's and liver doing it's job)
-Reverse if kidney's/liver are damaged
101
If the AUC is larger, then bioavailability is less T/F?
False
102
If rate of gastric emptying is slow then bioavailability is increased tTF?
False. If rate of gastric emptying is slow then bioavailability is reduced (ex. reduced absorption surface, destruction by low pH/gastric enzymes)
103
If rate of intestinal emptying (or intestinal motility) is low (statsis), bioavailability can't be increased anymore since it's at maximum T/F?
True
104
If rate of intestinal emptying is high (ex. diarrhea), bioavailability will be increased T/F?
False
105
Will there be increased absorption if the intestinal surface is reduced due to inflammation or surgical ressection?
No. The reverse is true. There will be decreased absorption in that case.
106
Can hepatic metabolism be increased or decreased?
-Yes it can be increased by inducers of enzymatic activity.
-It can be decreased by educers such as in cases of decreased hepatic function due to severe liver disease or effects of chemicals that inhibit hepatic metabolism
-Ex. Nitroglycerin would be heavily impacted by changes in hepatic metabolism because it's highly metabolized by the liver
107
The nutrient and caloric content, volume and temperature of the meal can all affect what?
Factors that affect a drug's ability to be able to disssolve, it's permeability (ability to cross the cell membranes) and speed of travel (transit) in the GI system are all affected
-Ex. Large volumes of liquids tend to distend the stomach and accelerate gastric emptying, whereas high-calories, high-fat meals are more likely to slow gastric emptying
-ALL OF THESE FACTORS CAN AFFECT THE BIOAVAILABILITY OF A DRUG ADMINISTERED VIA THE ORAL ROUTE
108
When things hang around in the stomach is bioavailability increased or decreased?
Decreased
109
The larger the surface area - the more layers/chances of absorption (ex. liver has less then intestines) T/F?
True
110
