Pharm Block 1 (Admin, Calculation, Fund) Flashcards
1
Q
What is a prescription?
A
A prescriber’s order for a specific patient
2
Q
Define “Sig”
A
“Let it be labeled (according to prescription), abbreviation for the Latin signature
3
Q
What are two safety categories?
A
Legend (RX) - requires PRESCRIPTION
Over the Counter (OTC) - considered safe for self-administration by the layman
4
Q
FDA determines if a drug should be legend or OTC based on what?
A
Safety considerations
5
Q
- What is another category of legal factors other than safety categories?
- Which agency controls and monitors drugs considered to have abuse potentials?
A
- Abuse
2. DEA
6
Q
Which agency approves what indications a drug is used?
A
FDA
7
Q
Define Labeled Use
A
FDA has approved a New Drug Authorization (NDA) saying the drug is safe and effective for the indication
8
Q
- Define Unlabeled Use
- May a prescribe legally prescribe a medication for an unlabeled use?
- If yes, what should it be based on?
A
- The use of a medication for an indication that has NOT been approved by the FDA
- Yes
- Decision on evidence, not on personal feeling or untested theories
9
Q
What does a PA need to consider when ordering?
A
- Make a specific diagnosis
- Consider the pathophysiology of the diagnosis
- Select therapeutic objectives
- Select a drug of choice
- Determine the appropriate dosing regimen
- Devise a plan for monitoring the drug’s action and determine an end point for therapy
- Plan a program of px education
10
Q
Graduate PAs may be privileged to write prescriptions for?
A
- Meds approved/recommended by the Pharmacy & Therapeutics (P&T) Committee
- Controlled substances scheduled II-V
- In-px care orders
- During FTX or deployment, may administer or prescribe any item stocked in the U.S. Army field medical set, kit or assemblage authorized at the level of assignment
- Meds reviewed and approved by the credentials committed for use
11
Q
What DoD form is used for prescription?
A
DD 1289
12
Q
What information is needed in Prescription body?
A
- Superscription (Rx)
- Inscription (Name & strength of drug)
- Subscription (qt prescribed)
- Signature (Sig) (Directions)
- Refill information
13
Q
What information needs to be included in prescriptions for children under 12?
A
Age age weight
14
Q
- What do controlled substances contain?
2. In what situation, do controlled substances contain the statement?
A
- Qt numerically and spelled out in written words
2. If from non-physicians
15
Q
What are two types of Drug Names?
A
- Trade/brand: Exclusively used by one company/manufacture and protected by trademark law (Mortin)
- Generic: public nonproprietary name, approved by FDA (ibuprofen) - NOT protected by trademark law
16
Q
DoD permits up to a ____ day supply for maintenance medications.
A
90 days
17
Q
How to provide clear directions for use (Sig)?
A
- Fewer doses/day = better compliance
- Complete directions reduce medication errors
- Avoid “Take as directed”
18
Q
Refills
- DoD and several states limit refills to _____ from the date on original prescription
- What are the limitations on refills for schedule II-V?
A
- One year
- II — NO refill
III-V — 5 times within 6 Mons, whichever occurs first
19
Q
How to reduce medication errors when prescribing controlled substances?
A
Have qt spelled out in numeric and written form
E.t. #20 (twenty) (Applies to DoD and state level
20
Q
What are the factors that encourage noncompliance?
A
- Asymptomatic diseases (hypertension)
- Frequency (more is worse)
- Difficult to follow directions
- Side effects
21
Q
Medical Abbreviations
Define ASA, ATC, BMD, BM, BS/BG, BSA
A
ASA - Aspirin ATC - Around the Clock BMD - Bone Mineral Density BM - Bowel Movement BS/BG - Blood sugar/Glucose BSA - Body Surface Area
22
Q
Diseases and Symptoms
Define HA, HTN, HOTN, N&V, SOB
A
HA - Headache HTN - Hypertension HOTN - Hypotension N&V - Nausea & Vomiting SOB - Shortness of Breath
23
Q
Timing of Administration Dosage Schedule
Define a, p, ac, pc, prn, state
A
a - before p - after ac - before meals pc - after meals prn - as needed/as necessary stat - immediately
24
Q
Dosage schedule
Q, BID, TID, QID, Q__h, no
A
Q - every BID - 2 times a day TID - 3 times a day QID - 4 times a day Q\_\_h - every \_\_ hrs nr - no refills
25
Dosage Form
Cap, Liq, Supp, Syr, Tab, Ung/oint, DAW, Gtts
```
Cap - capsule
Liq - liquid
Supp - suppository
Syr - syrup
Tab - tablet
Ung/oint - ointment
DAW - dispense as written
Gtts - drops
```
26
Measurement
Oz, tsp, tbsp, mcg, meq, qs
```
oz - ounce (30 mls)
tsp - teaspoon (5 mls)
tbsp - tablespoon (15 mls)
mcg - microgram
meq - milliequivalent
qs - add sufficient qt to make
```
27
Route of Administration
AAA/aaa, AD/ad, AS/as, AU/au, OD/od, OS/os, OU/ou, PO/po, SL/sl
```
AAA/aaa - apply to affected areas
AD/ad - right ear
AS/as - left ear
AU/au - both ears
OD/od - right eye
OS/os - left eye
OU/ou - both eyes
PO/po - by mouth
SL/sl - sublingual; under the tongue
```
28
Route of Administration
NPO, per neb, Rect/PR/pr, PV/pv, IM, IV, IVP, IVPB
```
NPO - nothing by mouth
per neb - by nebulizer
Rect/PR/pr - rectally
PV/pv - vaginally
IM - intramuscular
IV - intravenous
IVP - intravenous push
IVPB - intravenous piggyback
```
29
Define Adverse Drug Event
Any untoward medical occurrence associated w/ the use of a drug
30
1. Define Adverse Drug Reaction
| 2. Define Medication Error
1. Any unexpected, unintended, undesired, or excessive response to a medicine
2. Any preventable event —> inappropriate medication use or patient harm
Deaths due to medical errors — 8th leading cause of death in the US
31
Difference between Allergic rxn and Idiosyncratic rxn
Allergic rxn - an immunologic hypersensitivity occurring as the result of unusually sensitivity to a medicine (anaphylaxis - severe)
Idiosyncratic rxn: an abnormal susceptibility to a medicine that is perculiar to the individual (e.x. Anti-histamine causing excitement in a child rather than sedation)
32
1. What is Controlled Substance?
| 2. What is another name for Controlled Substance?
1. A drug or other substance, or immediate precursor, included in schedule I, II, III, IV or V
2. Scheduled
33
Controlled Substances Classification
What are Factors Determining Control of Schedules?
1. Potential for abuse
2. Pharmacological effect
3. Pattern of abuse
4. Scope, duration, and significance of abuse
5. Risk to the public health
6. precursor of a substance already controlled
34
Controlled Substances Classification
Who may designate medication(s) as locally controlled if they deem them subject to potential abuse or diversion (e.g., Viagra)?
Commanders
35
What are DEA requirements for Schedule II Controlled Substances?
1. Require a written prescription (must be signed by the practitioner)
2. NO federal limit on qt (but most states/insurance limit to 30 days)
3. 90 day supply for maintenance medications
4. NO federal time limit
5. Refills of a C-II is prohibited
36
Which must be presented to the pharmacists for review prior to the actual dispensing of the controlled substance?
Original C-II prescription
37
1. During emergency situation, is telephoned prescriptions for G-II is allowed?
2. If yes, how soon must prescribing practitioner provide a written and signed prescription to the pharmacist?
1. Yes
| 2. Within 7 days
38
What are three exceptions where a faxed prescription will serve as the original written prescription and no further prescription verification is required?
(All normal requirements of legal prescriptions are followed)
1. Compounded for the direct administration to a px (i.e. IV, IM)
2. For residents of Long Term Care Facilities (LTCF) directly to the dispensing pharmacy
3. For a px enrolled in a Hospice Care Program (Must note on the prescription that it is for a hospice px)
39
Who or what organization is responsible for the accountability of controlled substances in Garrison and/or Deployed Environments?
Garrison - pharmacy and nursing personnel
Deployed Environments - us (PA!)
40
FDA Pregnancy Categories
Define Category A
No harm, No evidence of risk in later trimesters
41
FDA Pregnancy Categories
Difference between Category B and Category C
B: Found no risk to the fetus (animal reproduction studies) & NO studies in pregnant women
C: Found an ADVERSE EFFECT on the fetus (animal reproduction studies) & NO studies in humans
But may be used in pregnant women despite potential risks
42
FDA Pregnancy Categories
Define Category D and X
D - Positive evidence of human fetal risk but may be used in pregnant women despite potential risks (Potential benefits > potential risks)
X - Found fetal abnormalities (studies in animals or humans), positive evidence of human fetal risk (Risk > Benefits)
43
New FDA Pregnancy and Lactation Labeling Categories
What are the three subsections in the labeling and what information need to be provided in each of them?
1. Pregnancy
- Dosing
- Potential risk to the developing fetus
- information about whether there is a registry that collects and maintains
- 3 sub-headings: Risk summary, Clinical Considerations, and Data
2. Lactation
- Provide Information about using the drug while breastfeeding
- 3 sub-headings: same as Pregnancy
3. Females and Males of Reproductive Potential
- Pregnancy testing, Contraception, and Infertility
44
Drug Regulations
Which Act established that manufacturers, pharmacists, importers, and physicians prescribing narcotics be licensed and required to pay a tax in 1914?
Harrison Tax Act
45
Which act regulates that drugs must now be shown to be safe before marketing?
Food, Drug and Cosmetic Act
46
What did Durham-Humphrey Amendment define?
What drugs require a prescription
47
Which act classifies controlled substances into 5 categories?
Which agency established?
Controlled Substances Act
DEA
48
DoD Formulary
1. What is the difference between BCF (Basic Core Formulary) and ECF (Extended Core Formulary)?
2. What is Non-Formulary (NF)
1. BCF: carried by all full service MTF pharmacies (a list of the pharmaceutical agents that are REQUIRED to be on local formulary)
ECF: carried if the service is offered
-includes medications supporting more specialized scopes of practice than those on the BCF
2. NF medication - provided at the formulary cost share if the provide supplies information showing that there is a medical necessity
49
What are the phases of Drug Development?
1. Preclinical
- Animal pharmacology and toxicology data are obtained
- Investigational New Drug (IND) application for human testing is submitted to the FDA
2. Phase I
- Clinical testing w/ Healthy Volunteers (20-80)
- testing drug tolerance and toxicity
3. Phase II
- Emphasizes effectiveness
- Limited # of pxs w/ the disease or condition for which the drug was developed are treated (100-200)
4. Phase III
- Large-scale multicenter clinical studies performed w/ the Final Dosage Form
- Side effect monitored
5. Phase IV
- detect serious unexpected adverse events and evaluate efficacy
50
What is Monographs?
- Summary of medications information
| - required by FDA for all medications
51
# Define Q3H
Define Q8H
Define QID
Q3H - 8 times a day
Q8H - 3 times a day
QID - 4 times a day
52
Standard Medication Administration Times/Frequencies
1. 4 times a day
2. Once a day, based on first documented dose
3. 2 times a day (without Q)
1. Q6H
2. Q24H
3. BID
53
The parts of the percentage represent ____ of Drug in ____ of Solution
Grams, 100ml
54
1% (w/v) solution or other liquid preparation
1g of drug in 100ml of solution
55
Any substance that brings about a change in biological function through its chemical action
Drug
56
Describes HOW a drug produces its effect and sometimes the drug is classified by this means
Mechanism of Action
57
1. What the body does to the drug
2. What the drug does to the body
3. Risk-Benefit Ratio
1. Pharmacokinetics
2. Pharmacodynamics
3. Used when considering the risk of the adverse effects produced by a drug in relation to its likely beneficial effects
58
What are the steps of Pharmacokinetics?
1. Absorption
- site of administration
2. Distribution (around the body)
- exerts a therapeutic effect (P and S sites of action)
- Be stored (in body fat depots)
3. Metabolism
- to active or inactive forms
4. Elimination (from the body)
- Metabolism to inactive form (via liver, lung, blood)
- Excreted (via kidney, GI tract, lungs)
ADME
59
List 5 examples of Pharmacokinetic Parameters
1. Bioavailability
2. V of Distribution
3. Drug Accumulation
4. Clearance
5. Elimination
60
What factors determine the access of a drug molecule to its site of action?
1. Route of administration
2. Extent and rate of absorption
3. Distribution of drugs in body compartments
4. Rate of metabolism and elimination from the system
5. Effects of protein binding and tissue binding
61
Most of drugs are ___ acids or ___ weak bases and their ability to move from an aqueous to lipid environment depends on their ____ and the __ of the solution
Weak, weak, charge, pH
62
1. Henderson-Hasselbalch Equation
| 2. What affects the degree of ionization and the rate of drug transport?
1. The relationship between pH and the ratio of acid to base
Low pKa = Strong Acid (HCl)
High pKa = Strong Base (MgOH)
2. The pH
63
pH effects on medications
1. The state of during (ionized or un-ionized)
pH 1, pKa & pH4.4, pH 7
2. ___ is normally mildly acidic (Normal range pH 4.6-8.0)
1. PH 1 - very little ionized drug
pKa & pH 4.4 - 50% ionized
pH 7 - most of drug ionized
2. Urine
64
___________ the urine will increase the elimination of an acidic drug
___________ of the urine will increase the elimination of a basic drug
Alkalinizing, Acidification
65
Routes of Administration
Enteral: Oral (PO) - most convenient, undergo first pass metabolism
Buccal, Sublingual (SL)
Parenteral - IV, IM, subcutaneous (SQ or SC)
Transdermal (TDRM) - patches through the skin
Inhalation (INH)
66
Absorption
Fraction of unchanged drug reaching the systemic circulation after ORAL administration
Mainly determined by
- Extent of Absorption
- First Pass Metabollism
Bioavailability
IV drugs —> almost 100% Bioavailable
67
Factors affecting passage of drugs across biological membranes-
1. Lipid-aqueous partition coefficient
- Drug ionization (acid - base)
- Partition coefficient of non-ionized form
2. Specific transport
3. Plasma Binding
4. Perfusion rate (blood flow)
68
First Pass Metabolism (Absorption)
1. Absorption by _____, Metabolism by ___ and/or ___
2. Primary site of drug metabolism
3. First-pass effect REDUCES ___________
4. Predominantly applied to _____ administered drugs
5. May limit efficacy if ______ by liver is large
1. GI tract, Liver and/or Bowel
2. Liver
3. Bioavailability
4. Orally
5. Clearance
Defensive Mechanism
69
First-Pass Effect
How to obtain better systemic absorption of a drug that demonstrates high first-pass effects?
1. Increase in drug dose
2. Alternate route of administration
3. Modification of dosage form as a delayed-release drug product
70
Routes of administration and their characteristics
1. 100% Bioavailability, Most rapid onset
2. Most convenient, significant First Pass
3. Bypass First Pass
4. Slow onset, bypass First Pass, Long Duration
1. IV
2. Oral
3. Sublingual
4. Transdermal
71
What are two plasma proteins that carry drugs and many hormones in the blood?
Albumin
| a1-acid glycoprotein
72
Plasma Protein Binding (Absorption)
Only which drug is active?
What are they available for?
Why is important regarding?
Only FREE drug is active (drugs NOT bound to plasma proteins)
To bind w/ receptors
To be metabolized or eliminated
Highly plasma protein bound drugs - ibuprofen (>99% PPB)
Drugs w/ narrow therapeutic index
73
What is Drug Modeling used for?
To describe drugs’ distribution behavior in the body
| Distribution
74
One Compartment Model
- Simplest
- Comprises all body tissues and fluids
- Assumes instantaneous distribution throughout the body
75
Two different examples of highly perfumed compartments that are treated as ONE compartment
```
Central compartment (Vessel Rich)
Plasma, Heart, Lungs, Liver, and Kidney
```
76
Two Compartment Model
The first compartment is the ______ and __________ tissue and the second compartment comprises ___________ tissues
The drug quickly enters ______ and perfused tissues
The drug redistributes into other tissues such as _______ that are _________to the drug
1. Blood & highly perfused, LESS accessible
2. Blood circulation
3. Brain, less accessible
77
Two different types of Two Compartment Model
Central (Plasma, Heart, Lungs, Liver & Kidney)
Peripheral (Fat, Muscle, CSF)
78
Volume of Distribution (Vd)
Equation?
- the volume in which the drug distributes (expressed in units of V)
- Evaluate extensive or limited distribution
- L or L/Kg
Where the drug goes in the body
Vd = F x Dose / Co
F: Bioavailability
Dose: weight of drug given (i.e. mg)
Co: concentration of drug in blood/plasma (i.e. mg/L)
79
Distribution
1. ____ Volume of Distribution suggests minimal drug distribution
2. ___ Volume of Distribution indicates extensive drug distribution into body tissues and fluids
1. Small
| 2. Large
80
1. How does protein binding affect the Volume of Distribution?
2. What is the major plasma protein involved in drug protein binding?
1. High protein binding (high affinity for protein) —> Reduced Vd
Decrease Plasma Proteins (low affinity for protein) —> increased Vd
2. Albumin
81
1. What is the function of Blood Brain Barrier (BBB)?
2. Capillaries are covered by _________
3. ————— from tight junctions
4. What drugs are more likely to cross BBB?
1. Limits the size and type of molecules that can enter the brain
2. Astrocytes
3. Endothelial cells
4. Highly lipid soluble
82
1. Can drugs cross placenta?
| 2. If yes, what facilitates entry to fetus?
1. Yes
| 2. Lipid solubility
83
What is the stage of pharmacokinetics that normally deactivate, detoxify reaction leading to less pharmacologically active products?
Metabolic reactions (Metabolism)
```
Phase I (Non-synthetic)
Phase II (Synthetic)
```
84
Phase I (Non-synthetic) Rxn
1. Examples of Rxns
2. Introduce or expose ________
3. Converts parent drug to a more ____________
4. Results in loss of _____________
1. Oxidations, Reductions, and Hydroxylations
2. A functional group
3. Polar metabolite
4. Pharmacologic activity
85
Phase II (Synthetic)
Conjugation reactions
Highly polar conjugates resulting in ___________________
Rapid drug elimination from the body
86
4 different types of metabolites (Metabolism)
1. Inactive metabolites
2. Metabolites that retain similar activity
3. Metabolites w/ altered activity
4. Bioactive metabolites
87
Types of metabolites
Pharmacologically active parent compound become inactivated or detoxified
Inactive Metabolites
88
What do metabolites that retain similar activity do?
Retain the pharmacological activity of their parent compound to a greater or lesser degree
89
What do metabolites w/ altered activity do?
Develop different activity from that of their parent drug
90
1. What is an inactive substance when taken that must be converted by metabolism before it has biologic activity
2. Example of this substance
3. What type of metabolites is it?
1. Prodrug
2. L-DOPA converted to dopamine
3. Bioactive metabolites
91
A large family of mixed function oxidase responsible for the majority of drug metabolism
Cytochrome P450 Enzymes
- Source on many drug interactions
- CYP3A4, CYP1A2
92
Cytochrome P450 System(Metabolism)
What does induction result in?
DECREASED pharmacologic action of the inducing drug and co-administered drugs (via acceleration of metabolism)
93
Cytochrome P450 System(Metabolism)
What does inhibition result in?
INCREASED pharmacologic action of the co-administered drugs or substrates
(by reducing the metabolism of substrates or co-administered drugs)
94
Geometric property of some molecules and ions
This molecule/ion is ___________ on its mirror image
__________ may have different actions and side effects
Chirality (stereoisomerism)
Non-superposable
Enantiomer pairs
95
Chirality
What is racemic mixtures?
Three roles in Pharmacology
equal mixtures of the enantiomers
1. Create new drug
2. Reduce side effects
3. Extend a patent
96
Two different types of Kinetics of Metabolism
Define them
1. Zero-Order Kinetics: rate of metabolism is DEPENDENT ON TIME
2. First-Order Kinetics: rate of metabolism is PROPORTIONAL TO DRUG CONCENTRATION
97
Characteristics of Zero-Order Kinetics
- Linear Pharmacokinetics (Graph)
- Drug cont. changes w/ respect to TIME at a constant rate; independent of drug concentration
- NO true half life
98
Characteristics of First-Order Kinetics
- Non-linear Pharmacokinetics (Graph)
- Rate of Elimination is PROPORTIONAL to Drug Cont.
- Half life is constant regardless of drug content ration
99
Characteristics of Non-Linear Kinetics
- Area under the curve (AUC) is NOT proportional to the dose
- Amount of drug excreted in the urine is NOT proportional to the dose
- Elimination half-life may increase at high doses
- Ratio of metabolites formed changes w/ increased dose
100
What are alterations in Drug Metabolism?
-Genetic Variability
-Age
-Nutrition (Grapefruit Juice INHIBITS intestinal CYP3A4)
-Concurrent Disease
A. Liver (effect on metabolism)
B. Kidney (effect on clearance)
C. Lung, thyroid and heart disease
101
Elimination
At the kidney, what determines re-absorption of drugs?
_______ compounds are poorly re-absorbed
Lipid solubility
Charged
102
Besides Kidney, Drugs and metabolites are also eliminated via:
- Feces
- Skin (sweat)
- Lungs (volatile drugs)
103
Elimination
1. What is the measure of the removal of drug from plasma?
2. How is it expressed as?
3. What determine drug half-life?
1. Clearance
2. Volume/time (i.e. mL/min)
3. Drug’s clearance and volume of distribution
104
What is the ratio of the rate of elimination by all routes to the concentration of drug in the biologic fluid?
Clearance (CI)
The volume of plasma that gets filtered of drug per unit
- GFR
- Creatinine Clearance
105
Elimination
Creatinine Clearance (CrCl)
1. An estimate of ________ based on a formula
2. Can be based on a ___________ (more accurate)
3. Estimation to estimate ________________
4. Use _________ to estimate
1. Renal function
2. 24 hour urine collection
3. Glomerular filtration rate (GFR)
4. Serum Creatinine (SCr)
106
A product of muscle metabolism produced at a constant rate and filtered at the glomerulus, where it undergoes limited secretion
Creatinine
107
Elimination
Cockcroft-Gault
CrCl = (140 - age) x wt (kg) (0.85 if female) / (Scr x 72)
108
1. Time necessary for drug concentration in plasma to decrease by one half
2. What is it dependent on?
1. Half life
| 2. Volume of Distribution (Vd) and Clearance (CI)
109
Situation where the overall intake of a drug is fairly in dynamic equilibrium w/ its elimination
Steady State
Absorption = Elimination
110
Elimination
What is the General Rule?
- 5 half-life for stead state and for washout
| - Changes in concentration do NOT alter half-life
111
General Rule (Elimination)
Q: Ibuprofen half-life = ~2 hr
How long should it take to achieve Steady State?
Q: if a drug has a half-life of 7 hours, how long will it take to get to steady state if the infusion rate is 30mg/hr?
1. 8-10 hours
| 2. 5 half-lives to reach steady state x 7 hours = 35 hrs
112
Drug Accumulation
In practice, if the dosing interval is shorter than _______, then the accumulation of drug will be detectable
Four half-lives
113
Concentration
If the dose or dosing interval of the drug is altered, the time required for the drug to reach stead state is _____, but the final steady-state plasma level changes _________
Same, Proportionately
114
3 Characteristics of Concentration
1. NO interval/Shorter Interval = LESS Fluctuation
- Same dosing rate but as an infusion
- The Fluctuations between C max and C min will be MINIMAL
2. Longer Internal = MORE Fluctuation
- Same dosing rate but at LONGER intervals
- The Fluctuations between C max and C min will be GREATER
3. Regardless, the average plasma concentration will be the SAME
115
Dose required to replace the amount of drug lost from the body so that a desired plasma concentration can be maintained
Maintenance Dose
116
Fixed Dose and Fixed Interval Dose (Concentration)
The goal of changing the dosing INTERVAL
- To achieve similar steady-state concentrations
| - ideal for limited dosage forms (oral doses)
117
Fixed Dose and Fixed Interval Dose
How can you maintain a steady therapeutic concentration?
Change the DOSE
118
Fixed Dose and Fixed Interval Dose
For what reasons are changing the DOSE and INTERVAL required?
1. For substantial dosage adjustment w/ limited dosage-forms
| 2. For narrow therapeutic index drugs w/ target concentrations
119
A higher dose of drug to promptly raise the concentration to a desired level or steady state concentration (Css)
Loading Dose
120
When is the loading dose used?
1. To achieve the therapeutic concentration of a drug in the plasma RAPIDLY, typically INITIALLY
121
After administration of the loading dose, why do you need to administer the drug at the maintenance dose rate?
To maintain the drug concentration at the desired steady-state
122
Definition
Response is proportional to receptor occupancy
Assumption
123
Definition
Amount of drug necessary to elicit a response
Potency
124
Define
Efficacy
Effectiveness
1. Drugs ability to produce a desired or intended result
| 2. The degree to which something is successful in producing a desired result
125
Clinically, _____ is much more important than _____ in determining a drugs usefulness
Efficacy, Potency
126
The concentration at which the drug elicits 50% of its maximal response in the population
EC50 of a drug
Potency of two drugs can be compared by determining their EC50
127
Graded Response
For continuous variables
- BP
- Enzyme activity
- Change in muscle tension
128
Quantal Response
Number of subjects showing an “all-or-nothing” response
- Pain relief
- Death
- Number anesthetized
129
The Maximal response that can be produced by the drug
Emax
130
Concentration-Response Relationships
EFFECTIVE or THERAPEUTIC DOSE (ED50 or EC50)
The dose or concentration of drug producing a desire effect
- Response equals to 50% of the maximum response (Graded response)
- effect in 50% of a population (Quantal response)
131
The dose or concentration of drug producing a TOXIC effect
Toxic Dose (TD50)
- response equal to 50% of the maximum response (Graded response)
- effect in 50% of a population (Quantal response)
132
The dose or concentration of drug that induces DEATH
Lethal Dose (LD50)
-effect in 50% of a population (Quantal response)
133
Therapeutic Index
1. The ratio of the median ____ dose or the median ____ dose to the median __________________
2. The higher the therapeutic index, the ____ the drug, ___ monitoring
3. As a general rule, drugs that have a ____ therapeutic index require lab monitoring to determine _____________
1. Toxic (TD50) and Lethal (LD50)
2. Safer, Less
3. Small (Narrow), Plasma concentrations
134
Drugs that produce a response by ACTIVATING a receptor
Agonists
135
Drugs that may act as either agonist or antagonist
Partial Agonists
136
Drugs that REDUCE or PREVENT the effects of normal physiologic cell regulators or agonists
Competitively or non-competitively
Antagonists (Blocker)
137
An agent that binds to the same receptor as an agonist BUT induces a pharmacological response OPPOSITE to that agonist
Inverse Agonist
138
Competitive Antagonists
- Reduces POTENCY of agonist, may reduce efficacy
| - bind to the same receptor site as the agonists
139
Irreversible Antagonists
- May or may not compete w/ the agonist
- PERMANENTLY antagonizes agonist (covalent bound)
- Reduces EFFICACY of agonist
140
A type of agonist that inhibits the molecules responsible for terminating the action of an endogenous agonist, potentials agonist activity
Indirect Agonist
Ex)
AChE degrades acetylcholine (ACh)
ACh stimulates Muscarinic (M) receptors
AChE inhibitors prevents the destruction of endogenous ACh
The result is increased cholinomimetic effects due to increase ACh survival
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Non-competitive Antagonists (Allosteric Antagonist)
- bind to a different site on the receptor
- indirectly block agonist or reduce affinity of agonist
- NOT overcome by increasing the dose of agonist
142
When a drug has one effect, and only one effect on all biological systems
Specificity
143
When a drug favors one receptor
Selectivity
- The greater selectivity a drug has for a specific receptor —> fewer adverse reactions it will cause
- (General rule) increase in dose of a drug —> decrease in its selectivity
144
Function of Down-Regulation
- Decrease in the number of receptors
- make cells LESS SENSITIVE to a hormone or another agent
Ex) insulin receptors can be decreased in type 2 diabetics
(Tolerance)
145
Desensitization
-result of down-regulation
Q: what is required to produce an effect of the same magnitude as the initial exposure with a smaller drug concentration?
Increased concentration of the drug
146
Function of Up-regulation
- increase in the number of receptors
- Make the cells MORE SENSITIVE
EX) uterine oxytocin receptors are increased during 3rd trimester of pregnancy
147
Super sensitivity/Hyper-reactivity
Enhanced physiological or biochemical response
148
Non-Receptor Medications
Drugs that compete by interacting w/ opposing regulatory pathways
Ex)
- Epinephrine and Acethycholine act on the sympathetic and parasympathetic ANS, respectively
- Their effects are antagonistic to each other
Physiologic Antagonist
149
Non-Receptor Medications
Function of Chemical Antagonist (Neutralizing Antagonist)
- Inactivates the agonist
- Makes the agonists NO longer capable of binding to and activating the receptor
Ex)
Protamine Sulfate binds to heparin type anticoagulants, inactivating these agents
150
Which act or amendment requires manufacturers to demonstrate safety and effectiveness before marketing a drug?
Kefauver-Harris Amendment
