CH2 Drug Action and Handling Flashcards
_______ are designed to do one thing and nothing else
_______ are designed to do lots of different processes
- Drugs are designed to do one thing and nothing else
- Vitamins are designed to do lots of different processes
Notes
- Dose effect curve
- Log dose-effect curve
- median effective dose, 50 % good, 50% no effect –> starting dose
- Potency: how many mg do you need to make something happen?
- Drug A vs drug B comparison –> both are equally efficacy… efficatious????
- Asparin: least potent (see chart)
- Which is least efficatious? Aspirin
- Which is the most potent? Morphine
- Which is most efficatious? Morphine, Demerol, Aspirin are all efficatious (See chart)
Notes
- Median LD50, 50% great, 50% not so great
- We figure this out because we want to know what will kill you verses what will help
- Therapeutic Index, ratio of what will kill people 50% of the time/50% kill them
- ED50 vs LD50, the broader the spread between these two drugs the safer the drug (See TI chart)
- The bigger the TI the safer the drug
- (Next week start is Mechanism of drugs)
Drugs are differentiated from inert chemicals, or chemicals necessary for ____ processes (such as vitamins).
life
Drugs have the ability to act _____ in biologic systems to accomplish a desired effect.
selectively
When drugs exert effects on _____ systems, we can ____ the response to the dose of the drug given.
biologic; measure
If we plot the relationship of the dose of a drug vs. the intensity of the effect on a graph, we get a ______ curve.
dose-effect
From the _____ effect curve, we may determine a drug’s relative potency and efficacy as compared to other similar drugs.
log-dose
______ is a function of the amount of drug (the dose) needed to produce an effect.
Potency
If drug A requires a smaller dose than drug B to produce the same effect, then drug A is more _____ than drug B.
potent
______ is the maximum intensity of effect that can be produced by a drug, regardless of the dose.
Efficacy
Once a specific dose produces the maximum effect, giving higher doses beyond that dose does not increase ______.
efficacy
After the “______”, increasing the dose only increases the probability of adverse effects.
plateau
According to the theraputic index, the dose required to produce a specified intensity of effect in 50% of the test subjects is termed the ________ (ED50)
Median Effective Dose
The dose required to produce death in 50% of the test subjects is termed ______ (LD50)
Median Lethal Dose
The ratio of a drug’s LD50 to its ED50 is known as the _______ (TI).
Therapeutic Index
If the value of the TI is small (a “narrow TI”), then toxicity with the use of that drug is more ____ (monitor closely).
likely
If the value of the TI is large ( a “wide TI”), then the drug will be considered ____ to use.
safer
Drugs do not impart a new function to the organism but merely produce the same action as, or block the action of, an agent that already exists in the body is termed the ______
Mechanism of Action of Drugs
Stimulation of receptors on a nerve generates an ______ and keeps the impulse going.
action potential
Drugs may facilitate the action potential and _____ the impulse during its transmission from nerve to nerve (via neurotransmitters) and its final destination (the effector organ).
amplify
Drugs may also ______ with the action potential and ____ or block the impulse during its transmission from nerve to nerve and its final destination.
interfere; weaken
_____ are chemical structures that interact with both naturally occurring (endogenous) substances and drugs.
Receptors
Interaction between receptors and drugs results in either _______ change or _____ of a secondary messenge
Conformation shape; release
________: Allows the drug inside the cell to produce the effect
(Topic:Drug-Receptor Interaction)
Conformation shape change
________: This messenger produces the effect
(Topic:Drug-Receptor Interaction)
Release of a secondary messenger
When a drug combines with a receptor, the end result is an ______ in function.
alteration
A drug when producing an enhancement of the function is known as an _______
agonist
A drug when inhibiting a function is known as an _______.
antagonist
________ counteract the action of agonists
Antagonists
_________ (compete with agonists) bind to receptors but produce NO effect.
• With increased concentration of the _____, the competitive antagonist can be overcome.
(an antidote exists)
Ex: epinepherine vs. beta blocker
Competitive antagonists; agonist
________ is the study of how a drug enters the body, circulates within the body and leaves the body and what factors influence its movements.
Pharmacokinetics
Four major steps in the body’s handling of a drug: “ADME”
- Absorption
- Distribution
- Metabolism
- Excretion
The ________ of a drug affects both the onset and duration of drug activity.
route of administration
________: The time it takes for the drug to have an effect
Onset of drug activity
_______: The length of time the drug continues to have an effect
Duration of drug activity
Drugs may be given by ______ of administration in which the drug is placed directly in the GI tract.
enteral routes
The _____ and _____ are enteral routes of administration.
Oral route: Rectal route
Advantages of the oral route administration:
- _____ and simplest way to introduce a drug
- ______ and most convenient
- _______ for absorption in small intestine
- Safest
- Least expensive
- Large area
Disadvantages of the oral route administration.
- ______ onset of action
- ______ can alter absorption
- ______ blood levels than other routes
- Drugs may be ______ in GI tract (ie. insulin)
- Slower
- Food/pathology
- Less predictable
- inactivated
Advantages of Rectal route of administration
- Allows use of different dosage _____ –Suppositories, creams, enemas
- Used if patient is _____ or unconscious. –Used for local and systemic effects.
- forms
- vomiting
Disadvantages of enteral route of administration:
- Poor and/or irregular ______.
- Poor patient ______
- absorption
- acceptance
Drugs given by ________ routes of administration in which the drug bypasses the gastrointestinal tract.
parental
All of the following are examples of _____.
- Intravenous (IV)
- Intramuscular (IM)
- Subcutaneous (SC)
- Intradermal (ID)
- Intrathecal (IT)
- Intraperitoneal (IP) – Inhalation (IH)
- Topical
Parenteral routes of drug administration
General Advantages fo Parenteral Routes of Administration are:
- _______, more predictable response
- Used for drugs which are _____ by GI tract – Used in emergencies, unconsciousness, nausea
- Rapid onset
- inactivated
General disadvantages of Parenteral Routes of Administration:
- ______ (if applicable) must be maintained
- Administration may be more difficult or _____
- Difficult to _____ the drug once administered
- Asepsis
- painful
- remove
Parenteral routes of administration may be _____ or ________.
topical; systemic
Topical route is administration for _____ effects
- _____ (steroid creams, anesthetic patches)
- _____ (strips, chips and gels)
- _____, ears, nose, throat (drops and sprays)
local
- Skin
- Subgingival
- Eyes
Administration for systemic effects examples:
- _____ (transdermal patches)
- _____, buccal and translingual (nitroglycerin)
- Skin
- Sublingual
________: As a drug is absorbed, distributed, metabolized and excreted, it must pass through various membranes
Drug-Membrane Transport
The ______ of drug that passes through a membrane and the _____ at which the drug passes are important.
amount; rate
The Drug-Membrane Transport helps determine the____ and ____ of activity of the drug as well as any variation in individual response to the drug.
onset; duration
Name the three Physico-chemical factors that influence the passage of a drug across our body membranes:
- Solubility (Water or Lipid)
- Degree of ionization
- pH
Lipid-soluble drugs easily move across body
membranes by _____ directly proportional to concentration gradient and degree of lipid solubility.
simple diffusion
_____ lipid soluble compounds attain high concentrations at the membrane and readily move across the membrane (from area of high concentration to area of low concentration).
Highly
Drugs that are weak _____ dissociate in solution and equilibrate into a non-ionized form and an ionized form.
electrolytes
The _____ form acts like a lipid-soluble compound and readily crosses body membranes
non-ionized
The_____ form acts like a water-soluble compound and crosses body membranes with difficulty
ionized
______: The transfer of a drug from the route of administration to the systemic circulation.
Absorption
These factors should be considered for absorption at the site of administration:
- Surface area
- Blood perfusion
- Membrane pH
______ is the transfer of a drug from the site of absorption to the body tissues and ultimate site of action. The route of administration, membrane permeability and drug solubility must be taken into consideration.
Distribution
______: Transformation of a drug from a lipid-soluble form to a more water-soluble form
Metabolism
Factors to consider for Metabolism:
- Hepatic portal
- Hepatic pathology effecting liver function
- Age
- Mechanisms of metabolism.
- Drug Half-life
- First-order kinetics
What are the different mechanisms of metabolism?
1. Active to Inactive
2. Inactive to Active
3. Active to Active
____ is when an active parent drug is transformed into an
inactive compound. It is the most common type of drug metabolism.
Active to inactive metabolism
______ occurs when an inactive parent drug (prodrug) is
transformed into an active compound.
Inactive to Active
An _______ mechanism of metabolism occurs when an active parent drug is converted to a second active compound (active metabolite).
(Hint: this drug remains in its fat soluble state, is long lasting, and passes through the liver several times.
Active to active
A ______ is the time required for a drug’s concentration in
the blood to fall to half of its original level.
drug half-life
A drug’s half-life is determined by whether it exhibits _____ or ____ as it is metabolized.
• First-order kinetics
• Zero-order kinetics
Drugs that fall under the catergory of _____ have a constant half-life regardless of the dose administered. In other words the ____ percent of drug is eliminated per unit of time.
first-order kinetics; same
A ________ drug has a half-life that can vary based upon the
dose of drug administered.
Zero-order kinetics
Good to know:
For some substances, the same amount of drug is eliminated per unit time. What this means is that with some drugs the liver enzyme systems can become saturated (overwhelmed). In these cases, the administration of a relatively large dose can lead to prolonged metabolism, prolonged activity and adverse effects.
This describes ___-order kinetics
Zero
Good to know:
Weight, age lifestyle, medications, and health status are all important to keep in mind when reviewing a health history.
Always keep in mind that not everyones liver functions the way that you think.
Good to know
______ is the elimination of a drug and/or its metabolites from the body.
Excretion
What are the factors to consider with excretion?
HINT: involves the kidneys
-Glomerular filtration
(kidneys filter excess fluid & waste from blood)
-Active tubular secretion
(transfer of materials from peritubular capillaries to the renal tubular lumen with energy)
-Passive tubular diffusion
(transfer of materials from peritubular capillaries to the renal tubular lumen without energy)
What are the five extra-renal routes of excretion?
Lungs
Bile
Mammary glands
Saliva
GCF
Gases are excreted across the ____ tissue by simple diffusion (i.e. general anesthesia).
lung
Systemically absorbed drugs are secreted into the ___ and are eliminated in the feces.
bile
Drugs are excreted into breast milk through _____.
mammary glands
Drugs are secreted into the _____, swallowed and placed in the GI tract again (reciprocal absorption)
saliva
The excretion of _____is used in dentistry in treating periodontal disease
GCF (Gingival Crevecular Fluid)
What are the drug interactions/drug-food interactions during absorption?
Effects on microflora: Antibiotics and oral contraceptives
Effects of chelation: Tetracyclines and dairy products
What are the drug interactions/drug-food interactions during distribution?
Effects on plasma protein binding sites: Coumadin (warfarin) and aspirin
What are the drug interactions/drug-food interactions during metabolism?
Liver enzyme induction: Dilantin (phenytoin), cigarette smoke
(speeds up liver function)
What are the drug interactions/drug-food interactions during excretion?
Competition for excretion routes: Penicillin and methotrexate
How should you determine the appropriate child’s dose using Clarks Rule?
weight (lb) x Adult dose/150
Good to know.
99% of the drug coumadin dose is absorbed in muscle. To counter this, the dosage has been increased. When Asprin is used in conjunction with coumadin, it extracts some of the absorbed coumadin from the muscle potentially causing an overdose.
Good to know.
When might a patient taking warfarin also take an aspirin?
this might occur in an older patient who takes a baby asprin a day in addition to a blood thinner. This is DANGEROUS
What natual food causes medication to stay in your liver longer by slowing down liver function?
grapefruit juice
Stimulating beta-2 receptors ONLY would result in which of the following?
a. increased salivation
b. decreased BP
c. bronchodilation
d. decreased heart rate
c.bronchodilation
The generic name is the name given to an approved drug by the pharmaceutical company that developed it.
True
False
False
Ionized compounds ( possessing a charge) are lipid soluble and easily passed through the bodies membranes.
True
False
False
Orally administered drugs are distributed to the liver first and are metabolized and inactivated to some extent before they reach general circulation and their intended sites of action. this effect is known as?
A) First-pass
B) Second-pass
C) Third-pass
D) Fourth-pass
A) First-pass
If drug A requires a smaller dose than drug B to produce 50% of the maximum effect, then drug A is less potent than drug B
True
False
False
Drugs work by imparting a new function to the host organism,a function that did not exist prior to the administration of the drug.
True
False
False
Which of the following government agencies requires quality standards in a drug manufacturing plants and determines what drugs may be sold only by prescription?
FDA
If an infant weighs 10 lbs and if the adult dose is 30 mg,according to clark’s rule,the dose of the drug for the infant should be?
2mg
Which of the following is false when concerning routes of drug administration?
A) One disadvantage of IV is drug irretrievability
B) The rectal route is the most convenient way to introduce a drug for systemic effects
C) Topical applications are administered to the skin, oral mucosa,and also sublingually
D) None
B) The rectal route is the most convenient way to introduce a drug for systemic effects
Cardiovascular disease is complicated by the presence of co-morbid disease, such as diabetes hyperlipidemia
True
False
True
During first order kinetics, the same percent of drug is eliminated per unit time.
True
False
True
In one mechanism by which drugs are metabolized , an inactive parent drug may be transformed into an active compound . The inactive parent drug is called?
A) metabolite
B) inducer
C) inhibitor
D) prodrug
E) none
D) prodrug
Which of the following is false concerning the oral route of drug administration?
A) least expensive and most convenient route of administration.
B) safest and simplest way to introduce a drug to the body
C) more predictable blood vessels than other routes of administration.
D) large area if absorption in the small intestine.
E) none
C) more predictable blood vessels than other routes of administration.
The route of administration of a drug affects both the onset and duration of the response?
True
False
True
The median dose effect (ED50) is the dose of drug required to produce a specified intensity of effect in 50%of the test subjects.
True
False
True
The LD50 is the dose of a drug required to produce death in 50% of the test subjects.
True
False
True
In one mechanism by which drugs are metabolized, an active parent drug may be transformed into yet another active compound. This new compound is called an active metabolite.
True
False
True
Four major steps in the body’s handling of a drug: “ADME”
- Absorption
- Distribution
- Metabolism
- Excretion
