NR565 NR 565 Midterm Actual Questions and Correct Answers
Q1
G-Protien coupled receptors and how they interact with drugs
Answer: G-protein coupled receptors (GPCR) interact with drugs through 7 regions of proteins
that span and
innervate the cell membrane and trap the molecule into the receptor site like an interwoven basket
(Insel & Sriram, 2018). Drugs can then enter this space and interact with the GRCP. A specific
interaction and binding with a site on one or more of the regions of proteins within the GPCR, and
drugs bound with the GRCP can stimulate the release of G proteins that can interact with various
effector proteins to create physiological responses within the body (Insel & Sriram, 2018). This
process
occurs through secondary messengers (such as cAMP) which creates the extracellular
interactions
produced by the drug binding to the GRCP
Q2
What neurotransmitters are excitatory?
Answer: amino acids such as glycine, aspartate, and glutamate are excitatory (Woo & Robinson,
p.16, 2016)
Q3
Which is the most common CYP enzyme in the body? What role does it play?
Answer: According to the textbook, the CYP3A4 is the most important enzyme in the body.
CYP3A4 is
responsible for the metabolism of more than 50% of medications and is considered a major drug
metabolizing enzyme
Q4
What is the clinical significance of being an ultra-rapid CYP2D6 metabolizer?
Answer: People who are ultra-rapid metabolizers have high activity of CYP2D6 enzymes that break
down certain
medicines rapidly and are likely to need different doses or even a different medicine. Drug dose,
response, and toxicity risk of beta-blockers, antidepressants, antiarrhythmics, and opioid
analgesics are
dependent on CYP2D6 pharmacogenetics (Ayazseven et al., 2020). Knowing the result of the
CYP2D6
test and which group the patient falls into such as poor metabolizers, intermediate metabolizers,
or
ultra-rapid metabolizers, will help nurse practitioners prescribe the right medication and dosage
for the
patient
, Q5
What would be the concern if a drug is a CYP450indicer? How that might affect the metabolism of
another drug the patient is taking?
Answer: Cytochrome P450 enzymes are in cells throughout the body, primarily found in liver cells
(Girvan &
Munro, 2016). These enzymes are essential for the metabolism of many medications. Cytochrome
P450
enzymes can act as an inducer or inhibitor of metabolism. When a medication induces the CYP450
enzyme that increases the rate of metabolism (Girvan & Munro, 2016). This can impact the
effectiveness of other medications. For example, medication A induces CYP450 enzyme activity,
therefore medication B will be metabolized quicker and have a less therapeutic effect
Q6
Explain the significance of a drug being an inhibitor of P-glycoprotein? (see text)
Answer: P-glycoprotein (P-gp) is the main barrier of the body and it affects the proper delivery of
drugs and
causes drug resistance in our body. P-gp is an efflux membrane transporter, that can be found
throughout the body and it controls the cellular uptake and the distribution of synthetic
substances,
chemicals, and toxins. Drugs are chemicals and P-gp hinders the absorption, permeability, and
retention of the drugs, extruding them out of the cells. This adversely affects drug therapies and
fails to
yield good results, for example in therapies like using chemo agents in cancer treatments. In this
case,
proper inhibition of P-gp is important to increase cellular uptake, transport, and half-lives of
drugs. The
drug is an inhibitor of P-gp that would help in the cost-effective treatment for disease conditions
without wasting an extra amount of medicines
Q7
What are some differences in drug metabolism in Asian populations?
Answer: One of the biggest differences in drug metabolism derives from the fact that Asian
populations typically
have reduced activity of the CYP450 2D6 and 2C19 enzymes (Woo & Robinson, 2016). Specifically,
the
2D6 isoenzyme is responsible for metabolism of antiarrhythmics, antidepressants, and
neuroleptics so
the metabolism of these drugs are slower than other racial groups (Woo & Robinson, 2016). Given
that,
the clinician would need to make sure they monitor this patient and adjust dosages as
appropriate. The
2C19 isoenzyme is responsible for metabolism of acids, bases, and neutral drugs (Woo &
Robinson,
2016)
Q1
G-Protien coupled receptors and how they interact with drugs
Answer: G-protein coupled receptors (GPCR) interact with drugs through 7 regions of proteins
that span and
innervate the cell membrane and trap the molecule into the receptor site like an interwoven basket
(Insel & Sriram, 2018). Drugs can then enter this space and interact with the GRCP. A specific
interaction and binding with a site on one or more of the regions of proteins within the GPCR, and
drugs bound with the GRCP can stimulate the release of G proteins that can interact with various
effector proteins to create physiological responses within the body (Insel & Sriram, 2018). This
process
occurs through secondary messengers (such as cAMP) which creates the extracellular
interactions
produced by the drug binding to the GRCP
Q2
What neurotransmitters are excitatory?
Answer: amino acids such as glycine, aspartate, and glutamate are excitatory (Woo & Robinson,
p.16, 2016)
Q3
Which is the most common CYP enzyme in the body? What role does it play?
Answer: According to the textbook, the CYP3A4 is the most important enzyme in the body.
CYP3A4 is
responsible for the metabolism of more than 50% of medications and is considered a major drug
metabolizing enzyme
Q4
What is the clinical significance of being an ultra-rapid CYP2D6 metabolizer?
Answer: People who are ultra-rapid metabolizers have high activity of CYP2D6 enzymes that break
down certain
medicines rapidly and are likely to need different doses or even a different medicine. Drug dose,
response, and toxicity risk of beta-blockers, antidepressants, antiarrhythmics, and opioid
analgesics are
dependent on CYP2D6 pharmacogenetics (Ayazseven et al., 2020). Knowing the result of the
CYP2D6
test and which group the patient falls into such as poor metabolizers, intermediate metabolizers,
or
ultra-rapid metabolizers, will help nurse practitioners prescribe the right medication and dosage
for the
patient
, Q5
What would be the concern if a drug is a CYP450indicer? How that might affect the metabolism of
another drug the patient is taking?
Answer: Cytochrome P450 enzymes are in cells throughout the body, primarily found in liver cells
(Girvan &
Munro, 2016). These enzymes are essential for the metabolism of many medications. Cytochrome
P450
enzymes can act as an inducer or inhibitor of metabolism. When a medication induces the CYP450
enzyme that increases the rate of metabolism (Girvan & Munro, 2016). This can impact the
effectiveness of other medications. For example, medication A induces CYP450 enzyme activity,
therefore medication B will be metabolized quicker and have a less therapeutic effect
Q6
Explain the significance of a drug being an inhibitor of P-glycoprotein? (see text)
Answer: P-glycoprotein (P-gp) is the main barrier of the body and it affects the proper delivery of
drugs and
causes drug resistance in our body. P-gp is an efflux membrane transporter, that can be found
throughout the body and it controls the cellular uptake and the distribution of synthetic
substances,
chemicals, and toxins. Drugs are chemicals and P-gp hinders the absorption, permeability, and
retention of the drugs, extruding them out of the cells. This adversely affects drug therapies and
fails to
yield good results, for example in therapies like using chemo agents in cancer treatments. In this
case,
proper inhibition of P-gp is important to increase cellular uptake, transport, and half-lives of
drugs. The
drug is an inhibitor of P-gp that would help in the cost-effective treatment for disease conditions
without wasting an extra amount of medicines
Q7
What are some differences in drug metabolism in Asian populations?
Answer: One of the biggest differences in drug metabolism derives from the fact that Asian
populations typically
have reduced activity of the CYP450 2D6 and 2C19 enzymes (Woo & Robinson, 2016). Specifically,
the
2D6 isoenzyme is responsible for metabolism of antiarrhythmics, antidepressants, and
neuroleptics so
the metabolism of these drugs are slower than other racial groups (Woo & Robinson, 2016). Given
that,
the clinician would need to make sure they monitor this patient and adjust dosages as
appropriate. The
2C19 isoenzyme is responsible for metabolism of acids, bases, and neutral drugs (Woo &
Robinson,
2016)
