NU 553
Comprehensive Resource To Help You Ace 2026-2027
Exams Includes Frequently Tested Questions With
ELABORATED 100% Correct COMPLETE SOLUTIONS
Guaranteed Pass First Attempt!! Current Update!!
1. Define potency? - Correct Answer: amount of drug required to produce
an effect
2. Define efficacy? - Correct Answer: maximal effect a drug can produce.
3. Define intrinsic activity? - Correct Answer: AKA efficacy of a drug; the
capacity of a drug to activate the receptor: ability to produce an effect.
4. Define drug selectivity? - Correct Answer: ratio of the dose
concentration producing the unwanted effect: the drug concentration
producing desired effect
5. Define therapeutic index? - Correct Answer: The ratio between the toxic
dose and the therapeutic dose of a drug, used as a measure of the relative
safety of the drug for a particular treatment.
6. What are dose-effect relationships? - Correct Answer: Relationship
between dose and probability of the occurrence of effect
,7. Define receptors? - Correct Answer: large molecules (usually proteins)
the interact and mediate the action of drugs
8. Importance of receptors? - Correct Answer: determine the relationship
between the dose and effect, the selectivity of drugs, and the actions of
pharmaceutical antagonists
9. Examples of drug targets? - Correct Answer: enzymes, ion channels,
nuclear hormone receptors, transporters, and DNA
10.What is the structure-activity relationship (SAR)? - Correct Answer:
relationship between a drug's chemical structure and the outcome it has on
the body
11.What type of responses do ion channels produce? - Correct Answer:
Rapid, short-acting (nicotinic-muscle contraction)
12.What are the types of ion channel receptors? - Correct Answer: ACh
(nicotinic), gamma-aminobutyric (GABA), excitatory amino acids (glycine,
aspartate, glutamate)
13.What are G-protein receptors - Correct Answer: present in cell
membranes. binding site, then controls what happens in cell after drug is
bound.
,14.Activation of G-proteins produce intracellular changes in the binding of the
G-protein receptor to other proteins that control response through other
molecules called? - Correct Answer: second messengers
15.Second messenger molecules include? - Correct Answer: cyclic
adenosine monophosphate (cAMP), Ca++, phosphoinositide, diacylglycerols
16.Three main subunits of G-proteins - Correct Answer: alpha, beta,
gamma,
17.Beta-adrenoceptors mediate the effect of? - Correct Answer:
epinephrine (make heart beat faster, stronger)
18.Intracellular cAMP affected by? (Increased heart rate, contractility) -
Correct Answer: caffeine
19.What happens when receptors are stimulated of desensitized? - Correct
Answer: Responsiveness to drug altered, Can limit amount of time a drug
can be used clinically and places patient at risk for rebound effects when a
drug is d/c
20.What are enzymes? - Correct Answer: biological molecules that
encourage specific chemical reactions in the body. Drugs act to stimulate or
inhibit specific enzymes
, 21.Do full agonists need to bind to all available receptors to produce maximum
response? - Correct Answer: NO, as little as 10% for some; the leftover
unneeded receptors are called "spare receptors"
22.Do antagonists produce a direct response? - Correct Answer: No, they
prevent other molecules (like agonists) from occupying the same site and
producing a response.
23.Beta-blockers act as antagonists at what receptor? - Correct Answer:
Beta-adrenoceptor
24.Why might a beta-blocker have little to no effect on a patient? - Correct
Answer: they lack adrenergic nerve activity and already have a lower heart
rate
25.How do antagonists effect the concentration-effect relationship for an
agonist acting at that same receptor site? - Correct Answer: They make
the agonist appear less potent
26.Most antagonists in clinical use are competitive reversible antagonists.
What does that mean? - Correct Answer: Higher concentrations of the
competing agonist can overcome the antagonist effects
27.These antagonists bind irreversibly with the receptor sites: - Correct
Answer: botulinum toxin, echothiophate, phenoxybenzamine
Comprehensive Resource To Help You Ace 2026-2027
Exams Includes Frequently Tested Questions With
ELABORATED 100% Correct COMPLETE SOLUTIONS
Guaranteed Pass First Attempt!! Current Update!!
1. Define potency? - Correct Answer: amount of drug required to produce
an effect
2. Define efficacy? - Correct Answer: maximal effect a drug can produce.
3. Define intrinsic activity? - Correct Answer: AKA efficacy of a drug; the
capacity of a drug to activate the receptor: ability to produce an effect.
4. Define drug selectivity? - Correct Answer: ratio of the dose
concentration producing the unwanted effect: the drug concentration
producing desired effect
5. Define therapeutic index? - Correct Answer: The ratio between the toxic
dose and the therapeutic dose of a drug, used as a measure of the relative
safety of the drug for a particular treatment.
6. What are dose-effect relationships? - Correct Answer: Relationship
between dose and probability of the occurrence of effect
,7. Define receptors? - Correct Answer: large molecules (usually proteins)
the interact and mediate the action of drugs
8. Importance of receptors? - Correct Answer: determine the relationship
between the dose and effect, the selectivity of drugs, and the actions of
pharmaceutical antagonists
9. Examples of drug targets? - Correct Answer: enzymes, ion channels,
nuclear hormone receptors, transporters, and DNA
10.What is the structure-activity relationship (SAR)? - Correct Answer:
relationship between a drug's chemical structure and the outcome it has on
the body
11.What type of responses do ion channels produce? - Correct Answer:
Rapid, short-acting (nicotinic-muscle contraction)
12.What are the types of ion channel receptors? - Correct Answer: ACh
(nicotinic), gamma-aminobutyric (GABA), excitatory amino acids (glycine,
aspartate, glutamate)
13.What are G-protein receptors - Correct Answer: present in cell
membranes. binding site, then controls what happens in cell after drug is
bound.
,14.Activation of G-proteins produce intracellular changes in the binding of the
G-protein receptor to other proteins that control response through other
molecules called? - Correct Answer: second messengers
15.Second messenger molecules include? - Correct Answer: cyclic
adenosine monophosphate (cAMP), Ca++, phosphoinositide, diacylglycerols
16.Three main subunits of G-proteins - Correct Answer: alpha, beta,
gamma,
17.Beta-adrenoceptors mediate the effect of? - Correct Answer:
epinephrine (make heart beat faster, stronger)
18.Intracellular cAMP affected by? (Increased heart rate, contractility) -
Correct Answer: caffeine
19.What happens when receptors are stimulated of desensitized? - Correct
Answer: Responsiveness to drug altered, Can limit amount of time a drug
can be used clinically and places patient at risk for rebound effects when a
drug is d/c
20.What are enzymes? - Correct Answer: biological molecules that
encourage specific chemical reactions in the body. Drugs act to stimulate or
inhibit specific enzymes
, 21.Do full agonists need to bind to all available receptors to produce maximum
response? - Correct Answer: NO, as little as 10% for some; the leftover
unneeded receptors are called "spare receptors"
22.Do antagonists produce a direct response? - Correct Answer: No, they
prevent other molecules (like agonists) from occupying the same site and
producing a response.
23.Beta-blockers act as antagonists at what receptor? - Correct Answer:
Beta-adrenoceptor
24.Why might a beta-blocker have little to no effect on a patient? - Correct
Answer: they lack adrenergic nerve activity and already have a lower heart
rate
25.How do antagonists effect the concentration-effect relationship for an
agonist acting at that same receptor site? - Correct Answer: They make
the agonist appear less potent
26.Most antagonists in clinical use are competitive reversible antagonists.
What does that mean? - Correct Answer: Higher concentrations of the
competing agonist can overcome the antagonist effects
27.These antagonists bind irreversibly with the receptor sites: - Correct
Answer: botulinum toxin, echothiophate, phenoxybenzamine
