MULTIPLE CHOICE
ANTIMICROBIALS (PHARM 1 EXAM
1) WITH RATIONALES 2025\2026
EXAM GRADED A+
An 18-year-old female patient is brought to the emergency department
due to drug overdose. Which of the following routes of administration is
the most
desirable for administering the antidote for the drug overdose?
A. Intramuscular.
B. Subcutaneous.
C. Transdermal.
D. Oral.
E. Intravenous. - ANSWER- E. intravenous
The intravenous route of administration is the most desirable
because it results in achievement of therapeutic plasma levels of the
antidote rapidly.
,Chlorothiazide is a weakly acidic drug with a pKa of 6.5. If administered
orally, at which of the following sites of absorption will the drug be able
to readily pass through the membrane?
A. Mouth (pH approximately 7.0).
B. Stomach (pH of 2.5).
C. Duodenum (pH approximately 6.1).
D. Jejunum (pH approximately 8.0).
E. Ileum (pH approximately 7.0). - ANSWER- B. Stomach (pH of 2.5)
Because chlorothiazide is a weakly
acidic drug (pKa = 6.5), it will be predominantly in nonionized
form in the stomach (pH of 2.5). For weak acids, the nonionized
form will permeate through cell membrane readily.
Which of the following types of drugs will have maximum oral
bioavailability?
A. Drugs with high first-pass metabolism.
B. Highly hydrophilic drugs.
C. Largely hydrophobic, yet soluble in aqueous
solutions.
D. Chemically unstable drugs.
E. Drugs that are P-glycoprotein substrates. - ANSWER- C. Largely
hydrophobic, yet soluble in aqueous solutions.
,Highly hydrophilic drugs have poor oral bioavailability, because
they are poorly absorbed due to their
inability to cross the lipid-rich cell membranes. Highly lipophilic
(hydrophobic) drugs also have poor oral bioavailability,
because they are poorly absorbed due their insolubility in aqueous
stomach fluids and therefore cannot gain access to the surface of
cells. Therefore, drugs that are largely hydrophobic, yet have
aqueous solubility have greater oral bioavailability because they are
readily absorbed.
Which of the following is true about the blood-brain barrier?
A. Endothelial cells of the blood-brain barrier have slit junctions.
B. Ionized or polar drugs can cross the blood-brain barrier easily.
C. Drugs cannot cross the blood-brain barrier through specific
transporters.
D. Lipid-soluble drugs readily cross the blood-brain barrier.
E. The capillary structure of the blood-brain barrier is similar to that of
the liver and spleen. - ANSWER- D. Lipid-soluble drugs readily cross
the blood-brain barrier.
Lipid-soluble drugs readily cross the blood-brain barrier because
they can dissolve easily in the
membrane of endothelial cells. Ionized or polar drugs generally
fail to cross the blood-brain barrier because they are unable to pass
through the endothelial cells, which do not have slit junctions.
, 40-year-old male patient (70 kg) was recently
diagnosed with infection involving methicillin-resistant S. aureus. He
received 2000 mg of vancomycin as an IV loading dose. The peak
plasma concentration of vancomycin was reported to be 28.5 mg/L. The
apparent volume of distribution is:
A. 1 L/kg.
B. 10 L/kg.
C. 7 L/kg.
D. 70 L/kg.
E. 14 L/kg. - ANSWER- A. 1L/Kg
Vd = dose/C = 2000 mg/28.5 mg/L = 70.1 L. Because the patient is 70
kg, the apparent volume of distribution in L/kg will be approximately 1
L/kg (70.1 L/70 kg).
65-year-old female patient (60 kg) with a history of ischemic stroke was
prescribed clopidogrel for stroke prevention. She was hospitalized again
after 6 months due to recurrent ischemic stroke. Which of the following
is a likely reason she did not respond to clopidogrel therapy? She is a:
A. Poor CYP2D6 metabolizer.
B. Fast CYP1A2 metabolizer.
C. Poor CYP2E1 metabolizer.
ANTIMICROBIALS (PHARM 1 EXAM
1) WITH RATIONALES 2025\2026
EXAM GRADED A+
An 18-year-old female patient is brought to the emergency department
due to drug overdose. Which of the following routes of administration is
the most
desirable for administering the antidote for the drug overdose?
A. Intramuscular.
B. Subcutaneous.
C. Transdermal.
D. Oral.
E. Intravenous. - ANSWER- E. intravenous
The intravenous route of administration is the most desirable
because it results in achievement of therapeutic plasma levels of the
antidote rapidly.
,Chlorothiazide is a weakly acidic drug with a pKa of 6.5. If administered
orally, at which of the following sites of absorption will the drug be able
to readily pass through the membrane?
A. Mouth (pH approximately 7.0).
B. Stomach (pH of 2.5).
C. Duodenum (pH approximately 6.1).
D. Jejunum (pH approximately 8.0).
E. Ileum (pH approximately 7.0). - ANSWER- B. Stomach (pH of 2.5)
Because chlorothiazide is a weakly
acidic drug (pKa = 6.5), it will be predominantly in nonionized
form in the stomach (pH of 2.5). For weak acids, the nonionized
form will permeate through cell membrane readily.
Which of the following types of drugs will have maximum oral
bioavailability?
A. Drugs with high first-pass metabolism.
B. Highly hydrophilic drugs.
C. Largely hydrophobic, yet soluble in aqueous
solutions.
D. Chemically unstable drugs.
E. Drugs that are P-glycoprotein substrates. - ANSWER- C. Largely
hydrophobic, yet soluble in aqueous solutions.
,Highly hydrophilic drugs have poor oral bioavailability, because
they are poorly absorbed due to their
inability to cross the lipid-rich cell membranes. Highly lipophilic
(hydrophobic) drugs also have poor oral bioavailability,
because they are poorly absorbed due their insolubility in aqueous
stomach fluids and therefore cannot gain access to the surface of
cells. Therefore, drugs that are largely hydrophobic, yet have
aqueous solubility have greater oral bioavailability because they are
readily absorbed.
Which of the following is true about the blood-brain barrier?
A. Endothelial cells of the blood-brain barrier have slit junctions.
B. Ionized or polar drugs can cross the blood-brain barrier easily.
C. Drugs cannot cross the blood-brain barrier through specific
transporters.
D. Lipid-soluble drugs readily cross the blood-brain barrier.
E. The capillary structure of the blood-brain barrier is similar to that of
the liver and spleen. - ANSWER- D. Lipid-soluble drugs readily cross
the blood-brain barrier.
Lipid-soluble drugs readily cross the blood-brain barrier because
they can dissolve easily in the
membrane of endothelial cells. Ionized or polar drugs generally
fail to cross the blood-brain barrier because they are unable to pass
through the endothelial cells, which do not have slit junctions.
, 40-year-old male patient (70 kg) was recently
diagnosed with infection involving methicillin-resistant S. aureus. He
received 2000 mg of vancomycin as an IV loading dose. The peak
plasma concentration of vancomycin was reported to be 28.5 mg/L. The
apparent volume of distribution is:
A. 1 L/kg.
B. 10 L/kg.
C. 7 L/kg.
D. 70 L/kg.
E. 14 L/kg. - ANSWER- A. 1L/Kg
Vd = dose/C = 2000 mg/28.5 mg/L = 70.1 L. Because the patient is 70
kg, the apparent volume of distribution in L/kg will be approximately 1
L/kg (70.1 L/70 kg).
65-year-old female patient (60 kg) with a history of ischemic stroke was
prescribed clopidogrel for stroke prevention. She was hospitalized again
after 6 months due to recurrent ischemic stroke. Which of the following
is a likely reason she did not respond to clopidogrel therapy? She is a:
A. Poor CYP2D6 metabolizer.
B. Fast CYP1A2 metabolizer.
C. Poor CYP2E1 metabolizer.
