NUSCTX TEST QUESTIONS WITH
ALL CORRECT ANSWERS LATEST
UPDATE
1. What is the difference between on- and off-target toxicities? - Answer-On target:
Toxic effect due to the drug interacting with the intended therapeutic target. Usually
dose is too high or there is chronic activation effects. Off target: Toxic effect due to the
drug interacting with an unintended biological target or unintended tissue.
2. For non-steroidal anti-inflammatory drugs like aspirin and ibuprofen that block
inflammation and fever, how does it reduce fever and inflammation? What types of
toxicity are associated with these drugs? Is this on- or off-target toxicity? - Answer-
Inhibits COX 1 and 2 and reduces proinflammatory eicosanoids such as prostaglandins,
prostacyclins, and thromboxanes. These are On-Target toxicities. Cox1 also mediates
prostaglandins levels of the gut which mediates the mucosal lining protecting your gut
from the acid. Without this, you are prone to gastric bleeding. Both therapeutic and toxic
effect happen through the same receptors.
4. Benadryl is prescribed as an anti-allergenic, but also causes drowsiness. How does
Benadryl cause its anti-allergenic effects? How does Benadryl cause drowsiness? Is
this on- or off-target? - Answer-Targets H1 (histamine) Receptor to regulate
inflammatory factors like NF-KB. Crosses the blood brain barrier, antagonize the
histamine receptor and caused drowsiness. On-target
5. Terfenadine (Seldane) was also an anti-histamine that was used to alleviate allergic
symptoms. However, it also caused increased incidence of heart-attacks. Why? Was
this an on- or off-target effect? - Answer-Its therapeutic effect was antagonizing the
histamine receptors. Its Off-Target effect was that it was inhibiting the hERG channel
which caused fatal cardiac arrhythmias.
6. Thalidomide was used as a morning sickness pill for pregnant women. However, it
ended up causing birth defects in a lot of babies born. How does thalidomide treat
morning sickness? What type of birth defects were observed? What was the
mechanism? Was this an on or off-target effect? - Answer-R-thalidomide stimulates the
GABA receptor to cause sedative effects. Off-target effect was that S-thalidomide
inactivates Cereblon (a protein) which helps produce IGF1. IGF2 and fibroblast growth
factor for LIMB GROWTH. Deformities and shortened limbs
, 7. Why is thalidomide now used for cancer treatment? - Answer-Thalidomide analogs
(lenalidomide) used for cancer therapy to inhibit the blood vessel development. Anti-
angiogenic properties
8. What are excitatory and inhibitory neurotransmitters and how do they work, i.e. what
receptors do they bind to and what happens when they bind? - Answer-Excitatory
increases transmembrane ion flow, inhibitory decreases transmembrane ion flow.
Excitatory binds to the ACH, voltage gated NA+ channel, and glutamate receptors,
inhibitory binds to the GABA receptor.
9. How do organophosphorus nerve agents like sarin cause their symptoms and
ultimately death? - Answer-Overstimulating of ACH receptor that leads to
desensitization and is internalized,leading to loss of neurotransmission and muscular
and respiratory paralysis, death.
10. What enzyme do OPs inhibit? What happens when that enzyme is inhibited in the
brain? What symptoms arise from inhibiting this enzyme? - Answer-Inhibits
Acetylcholinesterase (ACHe). Causes accumulation of acetylcholine at the synapse.
Hyperstimulates muscarinic and Nicotinic ACH receptors. Leads to salivating, vomiting,
tearing, urinating, defecating, convulsions, tremors.
11. How does inhibiting acetylcholinesterase help with Alzheimer's disease? - Answer-
Galantamine is an AChE inhibitor. Galanthamine increases acetylcholine levels in the
synapse to compensate for loss of neurons that produce acetylcholine
13. How does cocaine work? - Answer-directly inhibits dopamine transporter. Inhibit
uptake of dopamine, serotonin, and norepinephrine, increasing level of these
neurotransmitters at synapse. Causes hyper stimulation of dopamine, serotonin and
adrenergic receptors.
14. How does heroin work? - Answer-Stimulates the Opioid receptor
15. How does addiction happen? - Answer-Heightened dopamine levels over long-
periods of time will lead to desensitization of dopamine receptors requiring more
drug/more dopamine to get the same level of happiness.
1. What do toxicologists do? - Answer-Toxicologists work to assess and understand
how chemicals affect living systems. Mechanistic Toxicology (investigates metabolic
transformations of drugs or potentially hazardous chemicals), Descriptive Toxicology
(Toxicity testing, what dose is hazardous? Effect on human health), Regulatory
Toxicology (setting the rules and ensuring compliance)
2. What is the main purpose of toxicity testing? How do we apply the testing results? -
Answer-Assesses the concentration-dependent hazard a chemical may present.
Applied in the approval of product use and regulating allowable concentrations in the
environment.
ALL CORRECT ANSWERS LATEST
UPDATE
1. What is the difference between on- and off-target toxicities? - Answer-On target:
Toxic effect due to the drug interacting with the intended therapeutic target. Usually
dose is too high or there is chronic activation effects. Off target: Toxic effect due to the
drug interacting with an unintended biological target or unintended tissue.
2. For non-steroidal anti-inflammatory drugs like aspirin and ibuprofen that block
inflammation and fever, how does it reduce fever and inflammation? What types of
toxicity are associated with these drugs? Is this on- or off-target toxicity? - Answer-
Inhibits COX 1 and 2 and reduces proinflammatory eicosanoids such as prostaglandins,
prostacyclins, and thromboxanes. These are On-Target toxicities. Cox1 also mediates
prostaglandins levels of the gut which mediates the mucosal lining protecting your gut
from the acid. Without this, you are prone to gastric bleeding. Both therapeutic and toxic
effect happen through the same receptors.
4. Benadryl is prescribed as an anti-allergenic, but also causes drowsiness. How does
Benadryl cause its anti-allergenic effects? How does Benadryl cause drowsiness? Is
this on- or off-target? - Answer-Targets H1 (histamine) Receptor to regulate
inflammatory factors like NF-KB. Crosses the blood brain barrier, antagonize the
histamine receptor and caused drowsiness. On-target
5. Terfenadine (Seldane) was also an anti-histamine that was used to alleviate allergic
symptoms. However, it also caused increased incidence of heart-attacks. Why? Was
this an on- or off-target effect? - Answer-Its therapeutic effect was antagonizing the
histamine receptors. Its Off-Target effect was that it was inhibiting the hERG channel
which caused fatal cardiac arrhythmias.
6. Thalidomide was used as a morning sickness pill for pregnant women. However, it
ended up causing birth defects in a lot of babies born. How does thalidomide treat
morning sickness? What type of birth defects were observed? What was the
mechanism? Was this an on or off-target effect? - Answer-R-thalidomide stimulates the
GABA receptor to cause sedative effects. Off-target effect was that S-thalidomide
inactivates Cereblon (a protein) which helps produce IGF1. IGF2 and fibroblast growth
factor for LIMB GROWTH. Deformities and shortened limbs
, 7. Why is thalidomide now used for cancer treatment? - Answer-Thalidomide analogs
(lenalidomide) used for cancer therapy to inhibit the blood vessel development. Anti-
angiogenic properties
8. What are excitatory and inhibitory neurotransmitters and how do they work, i.e. what
receptors do they bind to and what happens when they bind? - Answer-Excitatory
increases transmembrane ion flow, inhibitory decreases transmembrane ion flow.
Excitatory binds to the ACH, voltage gated NA+ channel, and glutamate receptors,
inhibitory binds to the GABA receptor.
9. How do organophosphorus nerve agents like sarin cause their symptoms and
ultimately death? - Answer-Overstimulating of ACH receptor that leads to
desensitization and is internalized,leading to loss of neurotransmission and muscular
and respiratory paralysis, death.
10. What enzyme do OPs inhibit? What happens when that enzyme is inhibited in the
brain? What symptoms arise from inhibiting this enzyme? - Answer-Inhibits
Acetylcholinesterase (ACHe). Causes accumulation of acetylcholine at the synapse.
Hyperstimulates muscarinic and Nicotinic ACH receptors. Leads to salivating, vomiting,
tearing, urinating, defecating, convulsions, tremors.
11. How does inhibiting acetylcholinesterase help with Alzheimer's disease? - Answer-
Galantamine is an AChE inhibitor. Galanthamine increases acetylcholine levels in the
synapse to compensate for loss of neurons that produce acetylcholine
13. How does cocaine work? - Answer-directly inhibits dopamine transporter. Inhibit
uptake of dopamine, serotonin, and norepinephrine, increasing level of these
neurotransmitters at synapse. Causes hyper stimulation of dopamine, serotonin and
adrenergic receptors.
14. How does heroin work? - Answer-Stimulates the Opioid receptor
15. How does addiction happen? - Answer-Heightened dopamine levels over long-
periods of time will lead to desensitization of dopamine receptors requiring more
drug/more dopamine to get the same level of happiness.
1. What do toxicologists do? - Answer-Toxicologists work to assess and understand
how chemicals affect living systems. Mechanistic Toxicology (investigates metabolic
transformations of drugs or potentially hazardous chemicals), Descriptive Toxicology
(Toxicity testing, what dose is hazardous? Effect on human health), Regulatory
Toxicology (setting the rules and ensuring compliance)
2. What is the main purpose of toxicity testing? How do we apply the testing results? -
Answer-Assesses the concentration-dependent hazard a chemical may present.
Applied in the approval of product use and regulating allowable concentrations in the
environment.
