HOSMERIT
NR 565 MIDTERM EXAM | QUESTIONS & ANSWERS
(VERIFIED) | LATEST UPDATE | GRADED A+
G-Protein coupled receptors and how they interact with drugs
Correct 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.
What neurotransmitters are excitatory?
Correct Answer: amino acids such as glycine, aspartate, and glutamate are excitatory (Woo
& Robinson, p.16, 2016).
Which is the most common CYP enzyme in the body? What role does it play?
Correct 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. CYP3A4 can be found in the liver, as well as the
lining of the GI tract. Due to this location, food can also influence this CYP. One example of
this is grapefruit juice, which can inhibit CYP3A4.
Medications that are metabolized by CYP3A4 include antimicrobials, calcium channel blockers,
antihistamines, anticonvulsants, azole antifungals, and corticosteroids (Woo, & Robinson,
2016).
What is the clinical significance of being an ultra-rapid CYP2D6 metabolizer?
, Correct 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.
What would be the concern if a drug is a CYP450indicer? How that might affect the
metabolism of another drug the patient is taking?
Correct 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.
Explain the significance of a drug being an inhibitor of P-glycoprotein? (see text)
Correct 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.
It will help to shorten the treatment time and speedy recovery of the patient (Abebe et al., 2019;
Woo & Robinson, 2016).
Significance of a VCORC1 mutation for patients taking warfarin?
NR 565 MIDTERM EXAM | QUESTIONS & ANSWERS
(VERIFIED) | LATEST UPDATE | GRADED A+
G-Protein coupled receptors and how they interact with drugs
Correct 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.
What neurotransmitters are excitatory?
Correct Answer: amino acids such as glycine, aspartate, and glutamate are excitatory (Woo
& Robinson, p.16, 2016).
Which is the most common CYP enzyme in the body? What role does it play?
Correct 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. CYP3A4 can be found in the liver, as well as the
lining of the GI tract. Due to this location, food can also influence this CYP. One example of
this is grapefruit juice, which can inhibit CYP3A4.
Medications that are metabolized by CYP3A4 include antimicrobials, calcium channel blockers,
antihistamines, anticonvulsants, azole antifungals, and corticosteroids (Woo, & Robinson,
2016).
What is the clinical significance of being an ultra-rapid CYP2D6 metabolizer?
, Correct 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.
What would be the concern if a drug is a CYP450indicer? How that might affect the
metabolism of another drug the patient is taking?
Correct 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.
Explain the significance of a drug being an inhibitor of P-glycoprotein? (see text)
Correct 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.
It will help to shorten the treatment time and speedy recovery of the patient (Abebe et al., 2019;
Woo & Robinson, 2016).
Significance of a VCORC1 mutation for patients taking warfarin?
