Lab 7 Flashcards
define drug
a substance that brings about a change in biologic function through its actions on the body
most drugs do what to produce an effect
bind to receptors
define diluent
substances or solutions that are inactive ingredients added to a drug to obtain the required drug concentration and/or dosage form
define placebo
substances used to understand if the effect is from the drug or some other condition (a non drug related response)
the placebo repsonse can be positive or negative – may improve or deteriorate the tested conditions
define experimental bias
refers to the researchers prejudiced view/behavior/expectations that can subconsciously affect the results of the experiment
to eliminate bias, what is done
the experiment is conducted in such a way that the patients do not know what treatment they’re receiving (BLIND)
and in a double blind study neither the participators nor experimenters know who is receiving each treatment
how is a double blind study possible
by use of coded labels and making both the placebo and drug look identical
what animal species are ideal for experiments
easy to handle and inexpensive
a drug’s pharmacologic class accurately predicts what?
the potential pharmacodynamic interactions
what is gross screening
a scanning procedure on living organisms (animals) to evaluate a drug’s pharmacologic class
THE FIRST STEP TO EVALUATE THE EFFECTS OF A NEWLY SYNTHESIZED/ISOLATED SUBSTANCE
Name 4 advantages of gross screening
economical (limited # animals and time involved)
broad scope – many responses can be observed
early detection of acute toxicity of the new compound AND potency and duration of action can be estimated
permits oral OR parenteral routes
name 3 disadvantages of gross screening
-bias liability of the subject
-total reliance on dramatic event of a repsonse. a useful drug may be discarded bc of no obvious respnse
-CANNOT DETECT PERIPHERAL SYSTEM EFFECTS like decreased GI motility
name some animals that can be used for drug screening candidates
rat
mouse
hamster
rabbit
sheep
chimpanzee
define tremors
shaking – involuntary movement of muscle limbs
define fasciculation
small local involuntary muscle contraction ( mainly in abdominal area)
define clonic convulsions
alternating contraction and relaxation of voluntary muscles
(limbs extend out then pull in repeatedly)
define tonic convulsions
PROLONGED contraction of muscles
define ataxia
muscular incoordination (drunken gait)
define grasping
the ability to grasp on a screen (at about 45 degree angle)
define righting reflex
the ability to return to upright on all paws after it’s been placed on its back
define Ptosis
drooping eyelids
define chromodacryorrhea
blood in the tears due to increased capillary permeability
define blanching
paleness of skin due to vasoconstriction
define hyperemia
redness of the skin due to vasodilation
define cyanosis
blue skin due to excess carboxy-hemoglobin in the body
define piloerection
hair follicles erect (standing on end)
define micturation
urination
define lacrimation
tear production
define salivation
saliva production
when conducting a study, there are at least ___ types of groups:
2 types
experimental and control group
differentiate between the control group and the experimental group
experimental group receives the drug being tested (diluent and other excipients may be required to administer the drug to the animal)
the control group is used to compare the effects of other variables OTHER THAN the independent variable. increases the reliability of the results and removes bias. the group that DOES NOT RECEIVE THE DRUG – may receive a placebo or diluent that has no effect on the body. all other testing conditions remain the SAME
the experimenter should be blinded when performing an experiment to avoid bias.
this is particularly important in which studies?
behavioral studies
bias is introduced when……..
the experimenter unintentionally records the result of a particular group differently based on his/her prior knowledge about the treatments being tested
when………
the possibility of bias is greatly reduced preventing errors of measurement
the experimenter is blind to the treatment of the group
why is it important that all experiments include a control group
because experimental variability may be related to both the test individual and the experimenter
explain what a control group is
will be treated identically to the experimental group, EXCEPT for the variability of interest (drug) – will not be used in the control
if you are interested in the effects of a drug that is administered IV, what must you do?
include a control group that also receives an IV injection of an inactive solution (such as saline)
this allows the effects of the drug to be clearly evaluated.
if you evaluated the effect of the drug against a control group that was NOT injected, you are not really assessing both the effect of the drug and the effect of the injection procedure
it is possible that the injection procedure could have effects by itself such as production of endocrine, vascular, and behavioral changes (due to stress)
what is a “sham treatment”
the administration of an inactive drug or an ineffectual treatment
true or false
various types of control groups are included to help evaluate different aspects of an experiment
TRUE
placebos are used to determine if the observed effects are directly related to the drug or to the perception of the patient
define a placebo.
why is it used
a placebo is a drug or procedure that has no specific activity or active ingredient for the condition being treated
it’s used to determine if the observed effects are directly related to the drug or to the perception of the patietn
give 3 examples of placebos
saline
honey (oral)
PEGs (oral)
true or false
OFTEN, MULTIPLE CONTROL GROUPS ARE NEEDED
TRUE
how does the FDA define a pharmacological class
a group of active moieties that share scientifically documented properties such as:
-mechanism of action
-physiological effect
-chemical structure
define mechanism of action
pharmacologic action at the receptor, membrane, or tissue level
define physiologic effect
pharmacological effect at the organ, system, or whole-body level
define chemical structure
spatial arrangement of atoms, chemical bonds, and chemical groups in the drug molecule
what is the mechanism of action of diazepam
GABA increases frequency (nut not duration) of openings of GABA activated Cl- channels
what is the physiologic effect of diazepam
increased GABA activity
what is the chemical structure of diazepam
benzodiazepine
what is acetylcholine
the neurotransmitter released in the parasympathetic nervous system that produces central and peripheral effects
how are the effects of acetylcholine mediated?
be specific
via the nicotinic and muscarinic receptors
N1 receptors - located at NMJ
N2 receptors – located in the synapses of the ANS and in CNS and adrenal medulla
M1,M4,M5 receptors are in the CNS and affect memory, arousal, attention, and analgesia
M3 is present in smooth muscle of bronchial tissue, bladder, and exocrine glands
where are nicotinic receptors found
N1 - at NMJ
N2 - in synapses of the ANS, CNS, adrenal medulla
where are muscarinic receptors found
M1,M4,M5 – in the CNS. affect memory, arousal, attention, and analgesia
M3 - in smooth muscle of bronchial tissue, bladder, exocrine glands
M1 - gastric parietal cells
give 1 example of a cholinergic muscarinic agonist
what are its effects?
pilocarpine
produces tears, salivation, diarrhea, and piloerection
give 1 example of a cholinergic muscarinic antagonist
what are its effects?
scopolamine
dry mouth, no lacrimation, and agitation
where are dopaminergic receptors located? what do they control?
in the CNS
locomotion, cognition, and neuroendocrine secretion
what does dopamine regulate?
therefore, it is associated with….
voluntary movement, reward, and addictive behavior
therefore, associated with mania, depression, cognition, memory, learning, sleep, and food intake
dopamine agonists or antagonists affect the regulation of……
BLOOD PRESSURE
what does DRA stand for? what does it include?
DRA = dopamine receptor antagonists
includes the first generation anti-psychotics
what is a D2 receptor antagonist? give an example
haloperidol
antipsychotic, CNS depressant, hypoactivity, sedation, ataxia, loss of grasping, urinary retention, constipation
DOPAMINE belongs to a class of drugs called…..
inotropic agents
where are GABAergic receptors found? what do they do?
in the brain
coordinate the perception and response to painful stimuli
explain what a GABA RECEPTOR AGONIST does
binds to 1 or more GABA receptors and produces sedative effects (typically)
other effects include reduced anxiety (anxiolytic), anticonvulsant, muscle relaxant (reduce muscle contraction)
GABAergic neurons are located _____
in the brain
GABAergic neurons function to…..
REDUCE neuronal excitability by inhibiting nerve transmission
give an example of a GABA agonist
the sedative hypnotic barbiturates – pentobarbital, phenobarbital
explain what sedative hypnotic barbiturates are
they augment (amplify) the INHIBITORY GABAergic neurotransmission which reduces CNS activity, produces confusion, causes drowsiness, loss of righting, sedation, and ataxia
explain the mechanism of GABAergic receptors.
what class of drugs are GABA agonists
when GABA is bound to its receptor, it allows the passage of chloride which produces sedative effects by inhibiting nerve transmission and thus reducing neuronal excitability
barbiturates and benzodiazepines
