Chapter 1 Flashcards
how do we define drugs traditionally
substance that alters physiology of the body
is vit c a drug?
if consumed in bit form not if in orange
what is a psychoactive drug
Substances that impact the nervous system to alter a person’s mood, per-ceptions, or level of consciousness (as caffeine does) are often referred to as psychoactive drugs.
Substances that impact the nervous system to alter a person’s mood, per-ceptions, or level of consciousness (as caffeine does) are often referred to as …
psychoactive drugs
when gas is inhaled in the workplace what do we refer to it as
enviro toxin
Pharmaceutical drugs have at least three names what are they
chemical, trade name and generic name
7-chloro-1,3-dihydro-1-methyl-5-phenyl-2H-1, 4-benzodiazepin-2-one what can a chemist tell by this name
how the molecule is made up (joints of the drug molecule)
are chemical drug names always the same
the same drug will have different chemical names if different conventions are used.
how was the generic name made up initially
combining parts of the chemical name
what is the trade name
different formulations of the same drug (the drug in different states)
what is the street name for MDMA
ecstacy
All of modern science uses the … system and drug doses are nearly always stated in …
metric, milligrams
A milligram is … of a gram
1/1,000
what effects a drugs effects on the body? the amount fo the drug?
no the concentration = mg per kg
why are drug studies not always accurate
because Dif metabolisms = Dif concentrations of drug in the body = higher dose in animals
what is a dose–effect curve (DEC) or a dose–response curve (DRC)?
a graph that administers Dif dosages of drug (from so low you can hardly tell to so high nothing more is happening)
T: The range should include a dose so low that there is no detectable effect, a dose so high that increases in dose have no further effect, and a number of doses in between
dose–effect curve (DEC)
a small change in … doses will have a large effect
low not high
???scale on the horizontal axis is graduated loga-rithmically allows a wide range of doses to be reported and permits greater precision at the low end of the dosage range.
?
what’s on the vertical axis?
a continuous measure or a binary measure
Binary drug effects are handled by …
working with
groups of subjects.
4 types of names? do you know the difference?
trade name, street name, generic name and chemical name
what are 2 common ways of describing dosage response curves?
LD and ED50
what is ED50?
the median effective dose (effecting in 50% of populous)
what is LD?
median lethal dose
what is the LD1
dose that kills 1% of populous
what is ED99
effective in 99% of subjects
what is the ED 50 in a DRC with a continuous measure?
??refers to the dose that produces an effect that is 50% of the drug’s maximally effective dose.
what is ideal LD and ED levels
ones that the ED is very far from the LD
how do we describe the safety of a drug
The therapeutic index (TI; also known as the therapeutic ratio) is sometimes used to describe the safety of a drug.
how do we measure TI
ratio of ED to LD
do you want high or low TI
high
Drug safety may also be described as a ratio of the ….
ED99 and the LD1.
how do we describe the extent of a drugs effects
potency or efficacy (effectiveness)
When you are comparing two drugs that have the same effect, …. refers to differences in the ED50 of the drugs.
potencY
what is potency
the difference between the ED50 of the drugs
which drug is more potent ? higher or lower Ed50
lower
what does it mean to say a drug is 10x as potent
the nature and extent of the effect of LSA would be the same as that of LSD if you increased the dose of LSA by a factor of 10
… refers to a drug’s ability to produce a maximum, biologically functional response at its molecu-lar target,
Effectiveness
what is effectiveness of a drug
ability to produce max biological function at molecule target regardless of dose
why can’t you compare the potency of aspirin and morphine?
because at ED50 morphine is much more effective, they may both produce effects at the same ED50 and be equally potent but the extent of the effects are incomparable
what is antagonism in drug talk?
when one drug hinders the effects of another when mixed
how do you find out if 2 drugs are antagonistic ?
plotting two DRCs: one for the drug alone, and a second for the drug in the presence of the other drug
If the DRC for the first drug is ….) by adding the new drug, this result indicates antagonism between the drugs.
shifted to the right (i.e., the ED50 increases) ???
If adding the new drug shifts the DRC to the left (i.e.,
the ED50 decreases), the drugs are said to have an …
additive effect
what does an additive effect look like for DRC
shift to left
If, together, drugs have an effect that is greater than might be expected simply by combining their individual effects, a …, or …., exists.
superadditive effect, potentiation
if one drug has no effect alone but increases the effect of a second drug, what is happening
potentiation is clearly occurring.
drug interaction is defined in terms
of changes in …—shifts in the DRC indicated by changes in the ED50.
potency`
drug interaction can be defined in therms of ….. the ED50 may not change, but the maximum effect may increase or decrease`
effectiveness
what is a primary and a side effect
the effect for which a drug is taken the primary or main effect and any other effect, harmful or otherwise, is a side effect.
is there a clear distinction between main and side effects
the distinction between main and side effects is a matter of intention
the potential for a drug to be abused is a side effect
t
The study of how a drug moves around the body is called …
pharmacokinetics
what are the 3 processes of pharmokinetics
absorption, distribution and elimination
do drugs effect the whole body
no only sites of action
what happens if a drug does not reach its site of action
nothing happens
why Dif routes of administration
not only whether it gets to its site of action, but also how fast it gets there and how much of it gets there.
T: not only whether it gets to its site of action, but also how fast it gets there and how much of it gets there.
bioavailability
Getting drugs into the body can be accomplished by taking advantage of the body’s natu-ral mechanisms for taking substances inside itself (such as …), or the drug can be artificially placed under the skin by means of …
digestion, breathing, or absorption through mucous mem-branes
injection.
what is a parenteral route
administration involve injection through the skin into various parts of the body, using a hollow needle and syringe.
what does a drug have to be before it can be parenteral
liquid
what is this liquid called that powder is added to
vehicle
what liquid is most common vehicle
saline to match body to avoid irritating tissues
what is its not water soluble?
Dif vehicle
and the drug and vehicle are then injected to form a small ….
bubble, or bolus
4 common parental routes?
(a) subcutaneous, (b) intramuscular, (c) intra-peritoneal, and (d) intravenous.
the drug is injected to form a bolus just under the skin or cutaneous tissue.:T
subcutaneous
where is the subcutanous area in humans
usually done under the skin of the arm or thigh, but the hand or wrist is sometimes used to self-administer recreational drugs
usually done under the skin of the arm or thigh, but the hand or wrist is sometimes used to self-administer recreational drugs :T
skin popping
In the intramuscular (i.m.) route, the needle is inserted into …
a muscle, and a bolus is left there. (absorbed through muscle capillaries
where is intramuscular usually inserted
arm or bum
why no intramuscular in rats
muscle must be large
T:the needle is inserted directly into the peritoneal cavity
intraperitoneal route
what is the peritoneal cavity
contains visceral organs
what are 3 visceral organs
sleep, liver, intestines (through stomach only for animals)
what is the intravenous route
into bloodstream through vein
what is street name for intravenous route
mainlining
where does tourniquet go if elbow infection site
above elbow because veins carry blood to the heart
problem with intravenous IV
view can collapse if used to often
problem. with intravenous for rec drugs
may contain insoluble contaminants that get get lodged in eyes and lungs
a permanently implanted tube called a :T
catheter.
In … injections, for exam-ple, the needle is inserted into the nervous system between the base of the skull and the first vertebra. goes into CBS fluid then straight to nervous system
intrathecal
A drug may also reach the CSF through an intra-… injection directly into one of the brain’s ventricles, which are chambers filled with CSF
cerebroventricular
… injections may be used in which a drug is administered directly into brain tissue. These forms of drug administration are often done through a ….
intracerebra
cannula
what is a cannula
Cannulae are often attached to the skull using dental cement and can remain permanently implanted.
which method has the drugs impact you fastest
Generally, the volume of blood flow is greater to the peritoneal cavity than to the muscles, and it is greater to the muscles than under the skin. As a result, next to an i.v. injection, absorption is fastest from an i.p. injection and is slowest from an s.c. injection.
…2 can speed absorption from i.m. and s.c. sites because such factors increase blood flow to muscles and skin.
Heat and exercise
To be absorbed into the bloodstream, a drug must pass
through the walls of the …
capillaries.
why is the single cell wall of the capillary nessasy for drug absorption
can pass freely through pores of cap through diffusion
why is i.m injections faster then s.c
Areas that are serviced by many capillaries will absorb
drugs faster than areas that have few capillaries.muscles have more cap
how long does it take i.v injection to circulate around body
The body has about 6 liters of blood, and the heart pumps these 6 liters once a minute, so the drug in most i.v. injections is distrib-uted around the body within a minute after injection
why use a depot injection and what is it
the drug is dissolved in a high concentration in a viscous oil (often sesame oil) which is then injected into a muscle, usually in the buttock. if won’t comply to take antipsychotic drugs
how long does depot injection last?
4 weeks
what does a drug need to be for depot injection
highly lipid soluble
why is inhalation so effective in speed of drug effect
When drugs in the form of gases, aerosols, or fine mists are inhaled, they are very quickly absorbed through the capil-lary walls and enter the bloodstream to circulate around the body
where does blood go after heart
straight to lungs then after removing CO2 straight back to heart after absorbing o2 then from heart to brain (skips liver = fast effects
why are gases preferable to intravenous for controlling drug concentration?
the drug passes out of the blood into the air and is exhaled so that the concentration of the gas in the blood reflects the concentration in the gas that is breathed
3 drugs that are usually smoked?
Tobacco, opium, and marijuana
Dif between smoke and gas inhalation?
The major difference between smoke and gases is that the drug in the smoke particles will not revaporize after it is dissolved in the blood and, consequently, cannot be exhaled= must be eliminated a different way
cons of smoke inhalation?
damage to lungs effecting ability to absorb o2 and remove co2
when most substances burn in air, … gas is given off. … is a very toxic gas because it blocks the ability of the blood to carry oxygen.
carbon monoxide
how do vapours compare?
no carbon monoxide but same absorption method as smoke = can’t control level exhaled
what is the sniffing route called
intranasal administration or insufflation
what happens with intranasal ?
absorbed in nasal cavity and some down to lungs and digestive tract
how is drug absorbed during oral ingestion
through digestive system
what if put in mouth and not swallowed
absorbed through the buccal membranes, or mucous membranes of the mouth, not the gastrointestinal tract.
when would you want to use a suppository
when patient unconscious or vommitting
The gastrointestinal tract may also be entered via its other end (... administration).
intrarectal
with oral administration where is drug getting absorbed
Drugs that are soluble in gastric fluids and resistant to destruction by digestive enzymes may be absorbed from the stomach, but absorption is most efficient in the intestines
what determines the rate a swallowed drug is absorbed
the speed with which it gets through the stomach to the intestines.
does eating food slow or speed absorption
slow
what are membranes made up
lipid bilayer and proteins
is the head or the tail hydrophilic
head= loves water
what determines if a drug will get through the intestine tissue layer
the extent to which a drug can get through the lining of the intestine to the blood will depend on its ability to dissolve in lipids.
… drug molecules easily diffuse through membranes.
lipophilic
Different drugs have different degrees of lipid solubility that are usually expressed in terms of the …
olive oil partition coefficient.
olive oil partition coefficient: how is this found
drug put in solution half oil half water then separated and lipid soluble drugs will have higher concentration of drug in oil
what happens if a drug is electrically charged ions (to its solubility
when a molecule of a drug carries an electric charge, it loses its ability to dissolve in lipids.
what is Kpa
the ph where half of the drugs molecules become ionized
Most drugs are either weak acids or weak bases. what does this mean
???
what do we need to find out if a drug will be ionized in a certain Ph
need to know if its acid or base and its Kpa
the percentage of nonionized drug is all that is absorbed t or f
f the percentage of nonionized molecules determines the number of molecules available for absorption at any period of time and, therefore, determines the rate of absorption
If 50% of the molecules are not ionized, absorption will be …, but if 3% are not ionized, absorption will be …
rapid, much slower.
in transdermal admin what is hardest layer for drug to penetrate
epidermis due to keratin
what must drug be for transdermal admin
lipid soluble no water passed through epidermis
how does the patch work
transdermal patch separates the drug from the skin by a special membrane that limits the rate of absorp-tion
T: Even though most drugs get transported widely around the body by the blood, they tend to become concentrated in particular places and segregated from others.
distribution
what does fat do to a drug
acts like a sponge absorbs it and has no effect
where do lipid soluble drugs end up
in body fat around nervous system
what effects distribution of drugs
ion, lipid soluability, active passive trans, placental barrier, protein binding
when do bases and acids ionized
when in opposite solution
how does a ph difference of 1 effect drug concentration
10 time more concentrated on one side of the membrane compared to the other
how does a ph difference of 2 effect drug concentration
100 times
what causes the blood brain barrier
special cells in the central nervous system that wrap themselves around the capillar-ies and block the pores through which substances nor-mally diffuse
what substances can and can’t get passed blood brain bilayer
non lipid soulble can’t except for in some areas
the area …. of the medulla oblongata contains specialized cells that play an important role in detecting impurities or toxins in the blood and elicits vomiting in an attempt to rid the body of these substances
postrema
the … organ in the brain plays an important role in detecting hormone levels in the blood, especially those hormones involved in regulating the bal-ance of bodily fluids
subfornical
Mechanisms such as ion pumps, which maintain electrical potentials of nerve cells, are examples of ….
active transport systems.`
what happens if Some drug molecules become bound (attached) to these protein molecules
never reach active site or act as depositers as blood concentration of drug declines
There is a proportional relationship between the ratio of bound:unbound drug molecules and the drug’s lipid solu-bility (lipophilicity). what is this relationship
More lipophilic drugs tend to have a higher percentage of their molecules bound to blood pro-teins
can most active drugs be transported to the fetus
yes (high lipid sol = easier crossing)
Drug concentration in the blood of the fetus usually reaches 75% to 100% of that of the mother within … of administration
5 minutes
Small amounts of many drugs are eliminated in …3, but the major job of elimination is done by the …2
sweat, saliva, and feces
liver and the kidneys
what does the liver do
molecules are modified to form new substances useful to the body and where toxic molecules are changed into less harmful substances to be filtered out of the blood by the kidneys
how does the liver do it!?
enzymes
enzyme is a …., a substance that controls a certain chemical reaction
catalyst
how does the body control chemical reactions
The body controls chemical reactions by con-trolling the amount of enzyme available
other than liver where else are enzymes located
blood and brain or, as we will soon see, in the digestive tract
Most enzymes end in the suffix …
ase
what is metabolism
This process of biotransformation or the restructuring of molecules to rid them from the body
T: products of metabolism
metabolites
Where drugs are concerned, the metabolic process is sometimes called …
detoxification (although metabolites aren’t always less toxic )
metabolites are usually
more likely to ionize. why is this important to the kidneys
because ionized molecules cannot be reabsorbed into the blood through the nephron wall and, consequently, can be excreted more easily
what is first pass metabolism
Drugs that are absorbed into the bloodstream from the digestive system reach the liver before arriving at the heart.
which routes are not subject to first pass
nasal, anal or absorbed in mouth
what is the kidneys main job
to maintain water salt balances
what else do the kidneys do
take bad stuff from blood and excrete it
the kidneys can also excrete molecules of unwanted substances, the by-products of metabolism by liver enzymes
what it the functional unit of the kidney
the nephron
what is at both side of the nephron (and inside it)
Bowmans capsule, glomerulus
tube that goes to bladder
what goes through Bowmans capsule what stays
through= fluid
red and white cells in blood stays
The kidney works not by filtering impurities out but
by…
filtering everything out of the blood and then allowing selective reabsorption of what is required
what 2 mi=olecules are excreted inn urine
Unless they are reabsorbed by special transport systems, ionized or non-lipid-soluble substances will be excreted.
pH influences the degree of …
ionization which influences reabsorption
do acid or base go to blood or unine
urine = base blood = acid
how does the amount of the drug influence metabolism in the liver
lower dose= slower meta
what does the curve that plots the level of drug metabolizing look like
asymotote
HOW DO WE DESCRIBE THE WAY DRUGS ARE EXCRETED
with the half life
what does half life mean
Every 30 minutes, the body gets rid of half of the drug circulating in the blood, so the half-life of the drug in this example is 30 minutes
what is first-order elimination kinetics
the way drugs eliminate with the half life principle
what drug does not abide by half life
alcohol is eliminated at a constant rate
what is name for the way alc is eliminated
Xero order elimination kinetics
what are 6 reasons for variation in drug metabolisms
age, gender, species, past experience with drugs, and genetics.
Levels of a given enzyme can be … by previous exposure to a specific drug that uses that enzyme or some other enzyme system. This process, known as ….,
increased
enzyme induction
what does enzyme induction lead to
metabolic tolerance
what do heavy drinkers have a lot of
enzyme alc dehydronase = faster metabolism
When two drugs that use the same enzyme are introduced into the body at the same time, what will happen
the metabolism of each will be depressed because both will be competing for the enzyme
CAN THE the activity of an enzyme can be blocked by another drug
yes
disulfiram blocks acetaldehyde. what will happen
person will get sick from buildup of acetaldehyde which is toxic
how does drinking grapefruit juice alter drug consumption
blocks drug enzyme and can significantly increase blood levels of those drugs. As a result, people should avoid drinking grapefruit juice if they are taking any of a number of medi-cations.
how does age influence drugging
Enzyme systems are not fully functional at birth and may take time to develop completely.= metabolize differently
how does theophylline found in tea influence babies vs adults dif
the liver of a newborn human first converts the-ophylline to caffeine and then metabolizes caffeine very slowly. In adults, theophylline is metabolized directly without this intermediate stage
why do old people have to lower drug use
less effective liver function
why is drug more dangerous for baby after cord is cut
While the child’s circula-tory system is connected to the mother, the mother’s liver can metabolize the drug. But if the baby is born and the umbilical cord is cut before all the drug is broken down, the drug remains in the infant’s body and is dependent solely on the baby’s immature liver for metabolism, a pro-cess that may take many days.
how do we plot drugs effects
time course (the drug effect is usually represented on the vertical axis, and time on the horizontal axis).
how does the rate of excretion differ
always stays same
how does absorption differ
depends of route of admin (shape of half life
more intense subjective experience, greater reinforcement, and an increased capacity for addiction : what route?
intravenous
If the function of a drug depends on maintaining constant blood levels, as with antibiotics, … is pre-ferred. If it is necessary to achieve very high levels for brief periods, the drug is best given ….
oral administration
intravenously.
T: too high a level, there will be an increase in unwanted side effects and no increase in the therapeutic effect. If the drug falls below a certain level, it will not have a therapeutic effect at all.
therepudic window
what is the therepudic window
too high a level, there will be an increase in unwanted side effects and no increase in the therapeutic effect. If the drug falls below a certain level, it will not have a therapeutic effect at all.
how can you stay in the therepudic window
a drug must be taken at the correct dose at regular intervals
lithium carbonate, which is prescribed to people with bipolar disorder what’s the problem with this drug
absorbed and excreted rapidly = narrow therepudic window
does tolerance increase at the same rate for all drugs
no
Tolerance to the toxic effects of morphine builds .., moving the curve for the effective dose closer to the curve for the toxic dose, increasing the risk of overdose and narrowing the therapeutic window
more slowly
