PHAR 230 - DBMS Practice Questions Exam
With Correct Answers
Under acidic conditions, which drug is lipid soluble? - ANSWER Weak acid
Under basic conditions, which drug is lipid soluble? - ANSWER Weak base
Clinical Application Question: Proton pump inhibitors are used to reduce
heartburn by inhibiting stomach acid secretion. Remember that aspirin has a
pKa of 3.5, meaning that it will be in the unionized, lipid soluble form of the drug
in environments that have a pH less than 3.5.
A person taking a proton pump inhibitor will change the pH of their stomach
from 1-2 to around 5. What do you think would happen if someone was taking
both a proton pump inhibitor and aspirin? - ANSWER The overall absorption of
aspirin will be decreased in someone who is taking a proton pump inhibitor. The
pH of someone's stomach who is taking a proton pump inhibitor (pH ~5) is
greater than aspirin's pKa, so the ionized, water soluble form of aspirin will
predominate and the drug will no longer be absorbed in the stomach. The pH of
the intestines is greater than 5, so aspirin will not be absorbed in the intestines
either.
P450 enzymes are used in which type of biotransformation reactions?
a) Phase 1 reactions
b) Phase 2 reactions
c) Both phase 1 and phase 2 reactions
d) Neither phase 1 or phase 2 reactions - ANSWER A
Clinical Application Question: Two individuals undergo surgery to repair
abdominal hernias. The first individual is a 70 year old male with liver disease.
The second individual is a 40 year old healthy male. Post-surgically, both
patients are given the same dose of codeine, however the 70 year old patient
continues to complain about pain, while the 40 year old patient does not. What is
one potential explanation that you could give for this difference between the two
patients? - ANSWER Remember that in the body codeine is bioactivated into the
pain-relieving entity morphine by CYP 2D6. Both increased age and liver disease
will decrease biotransformation enzymes. It is likely that the 70 year old male
with liver disease was unable to convert enough codeine into morphine to
experience relief of pain. Therefore, he may need either an increased dose of
codeine, or be given morphine instead of codeine.
,Drug X is a weak base with a pKa of 8. Which one of the statements regarding
Drug X is correct?
a) Drug X will be absorbed best in basic conditions
b ) The ionized form of Drug X is lipid soluble
c) In the stomach, Drug X will be unionized
d) In the intestine, Drug X will be predominantly in the charged form - ANSWER A
Which one of these statements regarding biotransformation is correct?
a) Phase 1 biotransformation involves conjugation reaction.
b) The enzyme CYP 2A6 biotransforms about 50% of clinically used drugs
c) An example of a phase 2 reaction is an oxidative reaction by CYP 3A4
d) Phase 1 reactions add or unmask a functional group - ANSWER D
What is a possible explanation for a calculated Vd of less than 14L in a 70kg
person?
a) The drug is only in the intracellular fluid
b) The drug may be bound to plasma protein
c) The drug is only in the total body water
d) The drug has accumulated in extravascular storage depots, such as fat -
ANSWER B
What is a possible explanation for a calculated Vd of greater than 42L in a 70kg
person?
a) The drug has distributed to an accumulated in extravascular storage depots
such as fat.
b) The drug has accumulated only in the intracellular fluid
c) The drug is being excreted
d) The drug is only distributing to the extracellular fluid - ANSWER A
Consider a drug that is being administered to give a blood concentration of 20
mcg/ml. If the body eliminates 50% of the drug over the next four hours, what will
the plasma concentration of the drug be at 4 hours? - ANSWER 10 mcg/ml.
If the body continues to eliminate 50% of the drug over the next 4 hours, what
will the plasma concentration of the drug be 8 hours after administration? -
ANSWER 5 mcg/ml.
If a dose of 150 mg is ordered and the concentration of the drug solution is 300
mg in 2 ml, what is the volume of the drug that will contain 150 mg? - ANSWER
150/(300/2) = 1ml.
A 3-year-old boy has a BSA of 0.71m2. The dosage for a given drug for a 40-year-
old man is 300 mg. What is the dosage for the child? Answer to the nearest
whole number. - ANSWER The dosage for the child is 123 mg. Child's dose =
(BSA of the child m2/1.73) x 300mg
, Non-compliance is a huge barrier to providing patients with the care they need.
What strategies do you think health care providers could implement to try to
increase the compliance rate of their patients and overcome this obstacle? -
ANSWER Education of the patient is key to improving compliance with drug
therapy. At each visit to a health care provider (e.g. physician, nurse, or
pharmacist), the patient should be instructed on why the drugs are prescribed
and how to take them. For drugs that are taken several times a day,
consideration should be given to whether a long acting preparation, perhaps
taken once a day, is available.
What is the correct definition of half-life?
a) The amount of time it takes for a drug to be completely removed from the
blood
b) The amount of time it takes for 50% of a drug to be removed from the blood
c) The amount of time it takes for drug input to equal drug output
d) The amount of time it takes for the drug to be completely absorbed into the
blood - ANSWER B
If you know that the ED50 for seizure control is 4 mg and the TD50 for sedation is
50 mg, what is the TI? What does it tell us about the drug toxicity? - ANSWER TI =
12.5. This means that there is a 12.5
-fold difference between the beneficial dose and
the toxic dose, which tells us that if the drug is taken correctly, it is improbable
that adverse
effects will occur
2: What does a TI of 2 tell us about the drug toxicity? - ANSWER Since there is
only a 2-times difference between the beneficial dose and the toxic dose, it is
much more probable that adverse effects
will occur with the use of this drug
Clinical Application Question: A patient has just come out of surgery and is on
morphine to alleviate the post-surgical pain. You realize that the patient's
breathing seems to be laboured. The patient is not on any other drugs. What
could potentially be occurring? - ANSWER Answer: The patient is likely
experiencing an adverse effect to the morphine, specifically an effect in a non-
target tissue is occurring. Morphine binds to opioid receptors in the brain,
relieving pain. Upon reading, you discover that opioid receptors are also found
in the respiratory center of the brain, and activation of these opioid receptors
will depress breathing. If the dose of morphine is lowered, the patient's
breathing should normalize.
Clinical Application Question: A patient comes in to the clinic complaining of
increased agitation, restlessness, and the feeling that their heart is racing. After
talking to the patient, you discover that the patient generally drinks about 4
large cups of coffee a day, and that they are currently trying to quit smoking
With Correct Answers
Under acidic conditions, which drug is lipid soluble? - ANSWER Weak acid
Under basic conditions, which drug is lipid soluble? - ANSWER Weak base
Clinical Application Question: Proton pump inhibitors are used to reduce
heartburn by inhibiting stomach acid secretion. Remember that aspirin has a
pKa of 3.5, meaning that it will be in the unionized, lipid soluble form of the drug
in environments that have a pH less than 3.5.
A person taking a proton pump inhibitor will change the pH of their stomach
from 1-2 to around 5. What do you think would happen if someone was taking
both a proton pump inhibitor and aspirin? - ANSWER The overall absorption of
aspirin will be decreased in someone who is taking a proton pump inhibitor. The
pH of someone's stomach who is taking a proton pump inhibitor (pH ~5) is
greater than aspirin's pKa, so the ionized, water soluble form of aspirin will
predominate and the drug will no longer be absorbed in the stomach. The pH of
the intestines is greater than 5, so aspirin will not be absorbed in the intestines
either.
P450 enzymes are used in which type of biotransformation reactions?
a) Phase 1 reactions
b) Phase 2 reactions
c) Both phase 1 and phase 2 reactions
d) Neither phase 1 or phase 2 reactions - ANSWER A
Clinical Application Question: Two individuals undergo surgery to repair
abdominal hernias. The first individual is a 70 year old male with liver disease.
The second individual is a 40 year old healthy male. Post-surgically, both
patients are given the same dose of codeine, however the 70 year old patient
continues to complain about pain, while the 40 year old patient does not. What is
one potential explanation that you could give for this difference between the two
patients? - ANSWER Remember that in the body codeine is bioactivated into the
pain-relieving entity morphine by CYP 2D6. Both increased age and liver disease
will decrease biotransformation enzymes. It is likely that the 70 year old male
with liver disease was unable to convert enough codeine into morphine to
experience relief of pain. Therefore, he may need either an increased dose of
codeine, or be given morphine instead of codeine.
,Drug X is a weak base with a pKa of 8. Which one of the statements regarding
Drug X is correct?
a) Drug X will be absorbed best in basic conditions
b ) The ionized form of Drug X is lipid soluble
c) In the stomach, Drug X will be unionized
d) In the intestine, Drug X will be predominantly in the charged form - ANSWER A
Which one of these statements regarding biotransformation is correct?
a) Phase 1 biotransformation involves conjugation reaction.
b) The enzyme CYP 2A6 biotransforms about 50% of clinically used drugs
c) An example of a phase 2 reaction is an oxidative reaction by CYP 3A4
d) Phase 1 reactions add or unmask a functional group - ANSWER D
What is a possible explanation for a calculated Vd of less than 14L in a 70kg
person?
a) The drug is only in the intracellular fluid
b) The drug may be bound to plasma protein
c) The drug is only in the total body water
d) The drug has accumulated in extravascular storage depots, such as fat -
ANSWER B
What is a possible explanation for a calculated Vd of greater than 42L in a 70kg
person?
a) The drug has distributed to an accumulated in extravascular storage depots
such as fat.
b) The drug has accumulated only in the intracellular fluid
c) The drug is being excreted
d) The drug is only distributing to the extracellular fluid - ANSWER A
Consider a drug that is being administered to give a blood concentration of 20
mcg/ml. If the body eliminates 50% of the drug over the next four hours, what will
the plasma concentration of the drug be at 4 hours? - ANSWER 10 mcg/ml.
If the body continues to eliminate 50% of the drug over the next 4 hours, what
will the plasma concentration of the drug be 8 hours after administration? -
ANSWER 5 mcg/ml.
If a dose of 150 mg is ordered and the concentration of the drug solution is 300
mg in 2 ml, what is the volume of the drug that will contain 150 mg? - ANSWER
150/(300/2) = 1ml.
A 3-year-old boy has a BSA of 0.71m2. The dosage for a given drug for a 40-year-
old man is 300 mg. What is the dosage for the child? Answer to the nearest
whole number. - ANSWER The dosage for the child is 123 mg. Child's dose =
(BSA of the child m2/1.73) x 300mg
, Non-compliance is a huge barrier to providing patients with the care they need.
What strategies do you think health care providers could implement to try to
increase the compliance rate of their patients and overcome this obstacle? -
ANSWER Education of the patient is key to improving compliance with drug
therapy. At each visit to a health care provider (e.g. physician, nurse, or
pharmacist), the patient should be instructed on why the drugs are prescribed
and how to take them. For drugs that are taken several times a day,
consideration should be given to whether a long acting preparation, perhaps
taken once a day, is available.
What is the correct definition of half-life?
a) The amount of time it takes for a drug to be completely removed from the
blood
b) The amount of time it takes for 50% of a drug to be removed from the blood
c) The amount of time it takes for drug input to equal drug output
d) The amount of time it takes for the drug to be completely absorbed into the
blood - ANSWER B
If you know that the ED50 for seizure control is 4 mg and the TD50 for sedation is
50 mg, what is the TI? What does it tell us about the drug toxicity? - ANSWER TI =
12.5. This means that there is a 12.5
-fold difference between the beneficial dose and
the toxic dose, which tells us that if the drug is taken correctly, it is improbable
that adverse
effects will occur
2: What does a TI of 2 tell us about the drug toxicity? - ANSWER Since there is
only a 2-times difference between the beneficial dose and the toxic dose, it is
much more probable that adverse effects
will occur with the use of this drug
Clinical Application Question: A patient has just come out of surgery and is on
morphine to alleviate the post-surgical pain. You realize that the patient's
breathing seems to be laboured. The patient is not on any other drugs. What
could potentially be occurring? - ANSWER Answer: The patient is likely
experiencing an adverse effect to the morphine, specifically an effect in a non-
target tissue is occurring. Morphine binds to opioid receptors in the brain,
relieving pain. Upon reading, you discover that opioid receptors are also found
in the respiratory center of the brain, and activation of these opioid receptors
will depress breathing. If the dose of morphine is lowered, the patient's
breathing should normalize.
Clinical Application Question: A patient comes in to the clinic complaining of
increased agitation, restlessness, and the feeling that their heart is racing. After
talking to the patient, you discover that the patient generally drinks about 4
large cups of coffee a day, and that they are currently trying to quit smoking
