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