, Question 1
A hospitalized patient with confirmed influenza A (H1N1) develops severe
pneumonia and is started on oseltamivir. Which virologic property best
explains why adding baloxavir marboxil could provide an advantage in this
patient?
A. Baloxavir inhibits viral neuraminidase, preventing release of progeny
virions from infected cells.
B. Baloxavir inhibits the cap-dependent endonuclease of the polymerase
acidic (PA) subunit, blocking a step upstream of neuraminidase-mediated
release.
C. Baloxavir inhibits M2 ion channel function, preventing viral uncoating
within the endosome.
D. Baloxavir inhibits host IMP dehydrogenase, depleting guanosine
nucleotides required for viral RNA synthesis.
Correct Answer: B - Baloxavir inhibits the cap-dependent
endonuclease of the polymerase acidic (PA) subunit, blocking a
step upstream of neuraminidase-mediated release.
RATIONALE
Baloxavir targets the PA cap-dependent endonuclease, halting viral
mRNA transcription before neuraminidase acts. Oseltamivir inhibits
neuraminidase (option A), amantadine/rimantadine target M2 (option
C), and ribavirin/mycophenolate affect IMP dehydrogenase (option
D).
Question 2
A patient with a history of recurrent genital herpes is prescribed daily
suppressive acyclovir. Which pharmacologic rationale best justifies using
valacyclovir instead when adherence is a concern?
A. Valacyclovir has a longer intracellular half-life of the active
triphosphate than acyclovir.
Page 2
, B. Valacyclovir is a prodrug with higher oral bioavailability, allowing less
frequent dosing while maintaining comparable acyclovir exposure.
C. Valacyclovir does not require activation by viral thymidine kinase, so
it retains activity against TK-deficient HSV.
D. Valacyclovir inhibits viral DNA polymerase without competing with
guanosine triphosphate, reducing host toxicity.
Correct Answer: B - Valacyclovir is a prodrug with higher oral
bioavailability, allowing less frequent dosing while maintaining
comparable acyclovir exposure.
RATIONALE
Valacyclovir is the L-valyl ester prodrug of acyclovir with ~3-5 fold
greater oral bioavailability, enabling twice-daily or once-daily
regimens. It still requires viral thymidine kinase activation (option C is
false), and the active moiety is acyclovir triphosphate with the same
intracellular half-life (option A is false).
Question 3
Which statement most accurately reflects the role of letermovir in CMV
management compared with ganciclovir?
A. Letermovir is preferred for treatment of active CMV end-organ disease
because it has fewer hematologic effects.
B. Letermovir is indicated for CMV prophylaxis in allogeneic
hematopoietic stem cell transplant recipients and targets the CMV
terminase complex.
C. Letermovir requires phosphorylation by the UL97 kinase for
activation, similar to ganciclovir.
D. Letermovir is contraindicated with cyclosporine due to a CYP3A4
interaction that reduces letermovir levels.
Correct Answer: B - Letermovir is indicated for CMV
prophylaxis in allogeneic hematopoietic stem cell transplant
Page 3
, recipients and targets the CMV terminase complex.
RATIONALE
Letermovir is FDA-approved for CMV prophylaxis in allogeneic
HSCT recipients and inhibits the CMV DNA terminase complex
(UL56/UL89), a distinct target. It is not used for active end-organ
disease (option A is false), does not require UL97 phosphorylation
(option C is false), and cyclosporine increases rather than decreases
letermovir levels via OATP/CYP3A4 inhibition (option D is false).
Question 4
A patient with chronic hepatitis B is started on entecavir. Which monitoring
parameter is most critical to assess for the development of the drug's
characteristic adverse effect?
A. Serum creatinine and estimated glomerular filtration rate
B. Serum lipase and amylase
C. Lactic acid and hepatic transaminases
D. Thyroid-stimulating hormone and free T4
Correct Answer: C - Lactic acid and hepatic transaminases
RATIONALE
Entecavir, like other nucleoside analogs, can cause lactic acidosis and
hepatic steatosis, particularly with decompensated liver disease, so
lactate and transaminases are key. Renal function matters for dosing
but is not the characteristic toxicity (option A). Lipase and thyroid
studies are not routine for entecavir (options B and D).
Question 5
Which direct-acting antiviral regimen is most appropriate for a patient with
chronic hepatitis C genotype 1a and compensated cirrhosis who is
treatment-naïve?
A. Sofosbuvir/velpatasvir for 12 weeks
Page 4
A hospitalized patient with confirmed influenza A (H1N1) develops severe
pneumonia and is started on oseltamivir. Which virologic property best
explains why adding baloxavir marboxil could provide an advantage in this
patient?
A. Baloxavir inhibits viral neuraminidase, preventing release of progeny
virions from infected cells.
B. Baloxavir inhibits the cap-dependent endonuclease of the polymerase
acidic (PA) subunit, blocking a step upstream of neuraminidase-mediated
release.
C. Baloxavir inhibits M2 ion channel function, preventing viral uncoating
within the endosome.
D. Baloxavir inhibits host IMP dehydrogenase, depleting guanosine
nucleotides required for viral RNA synthesis.
Correct Answer: B - Baloxavir inhibits the cap-dependent
endonuclease of the polymerase acidic (PA) subunit, blocking a
step upstream of neuraminidase-mediated release.
RATIONALE
Baloxavir targets the PA cap-dependent endonuclease, halting viral
mRNA transcription before neuraminidase acts. Oseltamivir inhibits
neuraminidase (option A), amantadine/rimantadine target M2 (option
C), and ribavirin/mycophenolate affect IMP dehydrogenase (option
D).
Question 2
A patient with a history of recurrent genital herpes is prescribed daily
suppressive acyclovir. Which pharmacologic rationale best justifies using
valacyclovir instead when adherence is a concern?
A. Valacyclovir has a longer intracellular half-life of the active
triphosphate than acyclovir.
Page 2
, B. Valacyclovir is a prodrug with higher oral bioavailability, allowing less
frequent dosing while maintaining comparable acyclovir exposure.
C. Valacyclovir does not require activation by viral thymidine kinase, so
it retains activity against TK-deficient HSV.
D. Valacyclovir inhibits viral DNA polymerase without competing with
guanosine triphosphate, reducing host toxicity.
Correct Answer: B - Valacyclovir is a prodrug with higher oral
bioavailability, allowing less frequent dosing while maintaining
comparable acyclovir exposure.
RATIONALE
Valacyclovir is the L-valyl ester prodrug of acyclovir with ~3-5 fold
greater oral bioavailability, enabling twice-daily or once-daily
regimens. It still requires viral thymidine kinase activation (option C is
false), and the active moiety is acyclovir triphosphate with the same
intracellular half-life (option A is false).
Question 3
Which statement most accurately reflects the role of letermovir in CMV
management compared with ganciclovir?
A. Letermovir is preferred for treatment of active CMV end-organ disease
because it has fewer hematologic effects.
B. Letermovir is indicated for CMV prophylaxis in allogeneic
hematopoietic stem cell transplant recipients and targets the CMV
terminase complex.
C. Letermovir requires phosphorylation by the UL97 kinase for
activation, similar to ganciclovir.
D. Letermovir is contraindicated with cyclosporine due to a CYP3A4
interaction that reduces letermovir levels.
Correct Answer: B - Letermovir is indicated for CMV
prophylaxis in allogeneic hematopoietic stem cell transplant
Page 3
, recipients and targets the CMV terminase complex.
RATIONALE
Letermovir is FDA-approved for CMV prophylaxis in allogeneic
HSCT recipients and inhibits the CMV DNA terminase complex
(UL56/UL89), a distinct target. It is not used for active end-organ
disease (option A is false), does not require UL97 phosphorylation
(option C is false), and cyclosporine increases rather than decreases
letermovir levels via OATP/CYP3A4 inhibition (option D is false).
Question 4
A patient with chronic hepatitis B is started on entecavir. Which monitoring
parameter is most critical to assess for the development of the drug's
characteristic adverse effect?
A. Serum creatinine and estimated glomerular filtration rate
B. Serum lipase and amylase
C. Lactic acid and hepatic transaminases
D. Thyroid-stimulating hormone and free T4
Correct Answer: C - Lactic acid and hepatic transaminases
RATIONALE
Entecavir, like other nucleoside analogs, can cause lactic acidosis and
hepatic steatosis, particularly with decompensated liver disease, so
lactate and transaminases are key. Renal function matters for dosing
but is not the characteristic toxicity (option A). Lipase and thyroid
studies are not routine for entecavir (options B and D).
Question 5
Which direct-acting antiviral regimen is most appropriate for a patient with
chronic hepatitis C genotype 1a and compensated cirrhosis who is
treatment-naïve?
A. Sofosbuvir/velpatasvir for 12 weeks
Page 4
