Pharmacology Flashcards
1
Q
Pharmacology and PT
A
- Optimal response to therapy
- Interaxns with rehab procedures
- Adverse effects
- Compliance
- Drug alternatives
2
Q
Pharmacotherapeutics
A
Use of specific drugs to prevent, treat or diagnose disease
3
Q
Pharmacokinetics
A
What BODY does to the drug: Absorbtion Distribution Metabolism Elimination
4
Q
Pharmacodynamics
A
What DRUG does to body:
=Mechanism of action
Drug/Ligand + Receptor –> Drug-Receptor Complex
5
Q
Toxicology
A
Side effects
6
Q
Pharmacy
A
Preparation and dispensing of drugs
7
Q
Chemical Name
A
Name of chemical composing drug
Ex: N-Acetyl-p-aminophenol
8
Q
Generic Name
A
Common name of drug, describes chemical compound.
*Never capitalized
Ex: acetaminophen
9
Q
Brand/Trade Name
A
Name of drug, chosen by marketers or pharmaceutical company
*Always capitalized
Ex: Tylenol
10
Q
Patent
A
Company that creates drug has rights to it for 7-10yrs
- ->generic versions
- same therapeutic use
11
Q
Drug Development
A
- What constitutes drug
- FDA (Efficacy + Safety)
- Animal studies (Preclinical tests)
- Human studies (Clinical trials - Phases I-III)
- New drug approval
12
Q
Clinical Trials
A
Drug testing conducted on humans post animal studies of efficacy + safety:
Phase I: Small # healthy indiv (<1 yr)
*Effect, dosage, pharmacokinetics
Phase II: Limited # with target disease (2 yrs)
*Efficacy of treating specific disease
Phase III: 1000-3000 pts with target disease (3yrs)
*Efficacy + Safety in larger population
Phase IV: General population (Indefinite)
*Monitor problems post approval
13
Q
OTC Medication
A
- Availability/convenience
- High safety profile (lower dose = harder to harm)
- Note in patients
- PT implications
- Interaxns with other drugs (doubling up)
14
Q
Controlled Substances
A
Drugs with abuse potential, decreases with higher schedule:
Sched I - High Abpot / No med use Sched II - High Abpot / Some med use Sched III - Lower Abpot / Med use Sched IV - Lower Abpot / Med use + barbituates Sched V - Derivatives of high Abpots
15
Q
Schedule I
A
Controlled substances with highest abuse potential
*No medical use
Ex: Heroin, LSD, Marijuana (THC), MDMA
16
Q
Schedule II
A
Controlled substances with high abuse potential
*Some medical use
Ex: Morphine, Methadone, Methamphetamine,
Oxycontin
17
Q
Schedule III
A
Controlled substances with lower abuse potential
*Medical use
Ex: Codeine, Anabolic Steroids, hydrocodone
18
Q
Schedule IV
A
Controlled substances with low abuse potential
*Medical use + barbituates
Ex: Meprobromate, phenobarbitol, alprazolam,
diazepam
19
Q
Barbituates
A
CNS depressant
- Sedation
- Anesthetic
- Mild analgesic effects
20
Q
Analgesic
A
Painkiller
Ex: acetaminophen, NSAIDs, opioids
21
Q
Schedule V
A
Controlled substances with lowest abuse potential
*Contain derivatives of high abuse medicines
Ex: Codeine cough syrup, antidiarrheal preps,
phenergan
22
Q
Dose
A
Quantity of drug administered at one time
*Concentration of drug at receptor site
23
Q
Dosage
A
Administration of drug per unit of time
*How much to give (BID/SID/etc.)
24
Q
Dose-Response Curve
A
Relation between dose administration (magnitude of drug) and observed response
–>Shows effect of drug at any given dose
Plotted as Dose (x) vs Effect/Response (y)
- Threshold
- Potency
- Max effect
25
Drug Response
Extent to which drug reaches intended effect
26
Potency
Measure of drug dose needed to produce a therapeutic effect
*Potency does not equal efficacy
Higher = less drug needed for target effect
Lower = more drug needed for target effect
27
Subtherapeutic
Threshold, dose less than amount needed to produce target effect
28
Max Effect
Point at which increase in dose will not increase effect
29
Dose-Response Function
-Must specify dose and species
-One drug can have multiple
-Larger dose doesn't equal greater magnitude of
response (due to max effect)
Max effect = no increase in response with
increase in dose
30
Quantal Dose-Response Curve
Relation between drug concentration in blood (x) and response percentage of a population (y) to a specified effect chosen for the drug.
-Determines relative safety and efficacy of a particular drug
ED50
Therapeutic Effect
TD50
Toxic Effect
31
ED50
(Median Effective Dose); Quantal D-R Curve
= Min dose required to produce desired effect in 50% of the
population
32
Therapeutic Effect
Point at which dose of drug has effect on the body
33
TD50
(Median Toxic Dose)
= Min dose required to produce toxic effect in 50% of the
population
34
Toxic Effect
Point at which dose of drug becomes harmful to the body
35
Therapeutic Index
Ratio of dose that causes toxicity to dose that causes desired effect in a population
TI = (TD50 / ED50)
36
Absorption
1st step of pharmacokinetics
- Depends on:
- Route of admin
- Drug factors (lipid/water sol, size, ionization)
- Body factors (SA, pH, vascularity)
37
Bioavailability
Percentage of drug that reaches bloodstream
* Oral ~ 50%
* IV (Direct) ~ 100%
38
Routes of Administration
1. Enteral = GI Tract
- Oral
- Sublingual
- Rectal
2. Parenteral = Everything else, *more direct
- Inhalation
- Injection (IV, IM, IT, SC)
- Topical
3. Transdermal (Placed on skin --> bloodstream)
4. Implanted drug delivery
5. Controlled release preparations
6. Targeted drug delivery
39
Enteral Administration
(Route of administration, GI Tract)
1. Oral:
- Safe, easy
- Ltd absorption, 1st pass metab to liver, compliance
2. Sublingual:
- Rapid onset, no 1st pass metab
- Must absorb into mucosa easily
3. Rectal:
- Local effect
- Incomplete absorption, irritation
40
Parenteral Administration
(Route of administration, Direct)
1. Inhalation
- Rapid onset, respiratory, increased SA
- Irritation, administration, compliance
2. Injection (IV, IM, IT, SC)
- Direct, rapid onset
- Infexn, self-administration
3. Topical
- Local effects
- Can be absorbed into bloodstream
41
Transdermal Administration
(Route of administration, Placed on skin --> Bloodstream)
- Steady, prolonged delivery
- Ltd, drug must penetrate skin unchanged
42
IA
(Intra-arterial)
| = Specific
43
SC
(Subcutaneous)
= Local response needed
Ex: Novacaine, insulin
44
IM
(Intramuscular)
Ex: Botox for spasticity
45
IT
(Intrathecal)
= subarachnoid space of spinal cord
Ex: Analgesics, spasticity
46
Implanted Drug Delivery
Route of administration
-PCA Pump
47
Controlled Release Preparations
Route of administration
= Encapsulation to release in intervals, fewer manual
doses
48
Targeted Drug Delivery
Route of administration
-Monoclonal Ab's (Drug + Ab --> specific problem)
-Viral Transport
-Gene Therapy (Viral cells enter DNA, give new
instructions
-Enzyme Activation (Drugs only activated by specific
enzymes
49
Absorption Factors
Related to drugs:
Lipid/water sol Molecular/particle size
Ionization Physical form
Dosage form Formulation
Concentration
Related to body:
SA Vascularity
pH Other substances present
GI motility Functional integrity
Disease
50
Exogenous
Introduced to body from outside
51
Endogenous
Native to body
52
Membranes that Affect Absorption and Distribution
Based on lipid solubility:
1. GI --> Bloodstream
2. ECF --> ICF
3. ICF --> ECF
4. Kidneys --> Bloodstream
53
Passive Diffusion
Water soluble: Drug crosses membrane via aqueous
channel
Lipid soluble: Drug dissolved through membrane
54
Distribution
2nd step of pharmacokinetics
- Affected by:
- Blood flow
- Capillary permeability
- Binding
55
Depot Binding
Binding of drug to substance besides site of action
- ->Need to increase dose to get desired effect
- ->Adverse/toxic effects
56
Vd
(Volume of Distribution of drug)
-If evenly dist, = to total body fluid volume
= how much of drug is in bloodstream
57
Membranes that Affect Distribution
- Cell membranes
- Capillary walls
- Blood brain barrier (Glial cells)
- Placental barrier (not real barrier)
58
Blood Brain Barrier
Series of unique properties of blood vessels in the nervous system that regulate movement of molecules between blood and neural tissue.
1. Glial (Support) Cells
- Astrocyte --> End feet form sheath around BV
2. Tight junctions of endothelial cells
3. Breaks --> detect chemicals
- Area Postrema (Medulla)
- Median Eminence (HT)
3. Purpose:
- Block toxins
- Maintain homeostasis of brain
59
Metabolism
3rd step of Pharmacokinetics
= Biotransformation of drug from parent compound into
metabolite
-1st Pass Metabolism
-Lipid-sol --> Water-sol for kidney excretion
*High = drug has less effect
Low = drug has more effect
59
Biotransformation
Chemical change of drug
| *Not really "broken" down
60
Metabolite
Daughter compound of drug
60
1st Pass Metabolism
GI Tract --> Portal Circulation --> Liver --> Target Site
*Bypassed by IV drug admin
61
First-Order Kinetics
Rate of metab & elim proportional to concentration of drug
*Higher dose --> Higher metab of drug
61
Zero-Order Kinetics
Constant rate of metab regardless of concentration of drug
*Higher does --> Metab stays the same
62
Enzyme Induction
Tolerance = Increase in concentration of enzymes to be able to biotransform drug
- Drug has less effect due to upreg of enzymes
- ->More drug required for same effect
62
Cytochrome P450 System
Component of drug metabolism, in liver / GI tract
-Diversified, nonspecific
-Phase I
Oxidation (+O2, -H+)
Reduxn (-O2, +H+)
Hydrolysis
-Phase II (Some drugs enter directly)
Conjugation = coupling to endogenous compound
-->Inactivation --> Water soluble
63
Elimination
4th step of Pharmacokinetics
Filtration system via kidneys:
- Nephron / Glomerulus / Bowman's Capsule
- 1L blood/min, 1cm3 urine produced
- Lipid-sol drug --> water-sol drug --> Excretion
*Lipid-sol drugs reabsorbed and return to liver until water-sol
64
CL Total
(Total Body Clearance)
Rate at which drug is eliminated from the body, sum of hepatic, renal, pulmonary, integumentary clearances
CL = 0.69 x (Vd / (t1/2))
65
Half-life (t1/2)
Time it takes for 50% of drug to be eliminated from bloodstream
t1/2 = 0.69 x (Vd / CL)
Percentages of original dose:
2 t1/2 = 75%
4 t1/2 = 94%
6 t1/2 = 98%
```
Ex: 100mg drug
1 t1/2 = 50mg (50% of orig dose)
2 t1/2 = 25mg (75% of orig dose)
3 t1/2 = 12.5mg
4 t1/2 = 6.25mg (94% of orig dose)
```
66
Steady State Concentration
Amt administered = Amt Eliminated
- Takes 5-6 t1/2
- Determined by dose, dose interval, t1/2
- ->predictable accumulation
*Repeated fixed dose = continuous oscillations in
plasma concentrations of drug
*Single fixed dose = single peak in plasma
concentration --> decline in drug level
67
Tolerance
Decreased response to effects of given amt of drug from previous exposure
- Pharmacokinetic: Enzymes (Cross-tolerance)
- Pharmacodynamic: Receptors/Neurotransmitters
= More drug for desired effect
68
Dependence
Drug use necessary for physiological/psychological well-being
69
Cytochrome P450 System
Component of drug metabolism, in liver / GI tract
-Diversified, nonspecific
-Phase I
Oxidation (+O2, -H+)
Reduxn (-O2, +H+)
Hydrolysis
-Phase II (Some drugs enter directly)
Conjugation = coupling to endogenous compound
-->Inactivation --> Water soluble
70
Elimination
4th step of Pharmacokinetics
Filtration system via kidneys:
- Nephron / Glomerulus / Bowman's Capsule
- 1L blood/min, 1cm3 urine produced
- Lipid-sol drug --> water-sol drug --> Excretion
*Lipid-sol drugs reabsorbed and return to liver until water-sol
71
CL Total
(Total Body Clearance)
Rate at which drug is eliminated from the body, sum of hepatic, renal, pulmonary, integumentary clearances
= 0.69 x (VD/(t1/2))
72
Half-life (t1/2)
Time it takes for 50% of drug to be eliminated
Percentages of original dose:
2 t1/2 = 75%
4 t1/2 = 94%
6 t1/2 = 98%
```
Ex: 100mg drug
2 t1/2 = 50mg
4 t1/2 = 25mg
3 t1/2 = 12.5mg
4 t1/2 = 6.25mg (94% of original dose
```
73
Steady State Concentration
Amt administered = Amt Eliminated
- Takes 5-6 t1/2
- Determined by dose, dose interval, t1/2
- ->predictable accumulation
*Repeated fixed dose = continuous oscillations in
plasma concentrations of drug
*Single fixed dose = single peak in plasma
concentration --> decline in drug level
74
Tolerance
Decreased response to effects of given amt of drug from previous exposure
= More drug for desired effect
75
Dependence
Drug use necessary for physiological/psychological well-being
76
Drugs
Exogenous substances that mimic endogenous substances
77
Receptor
Protein with binding site for endogenous substances
78
Ligand
Substance capable of binding to a receptor
Ex: Drug, hormone
79
Selectivity
Enzymes: Nonspecific
Receptors: Very specific
80
Affinity
Drug ability to bind to receptor
| -Could block or open
81
Neurotransmitters
Acetylcholine
Norepinephrine
GABA
82
Agonist
=Opener
Exogenous ligand that binds receptor & causes biological effect
-Has affinity + efficacy
83
Antagonist
=Blocker
Exogenous ligand that binds receptor and blocks effect
-Has affinity + efficacy (if intended effect was to block)
