Antivirals Practice Questions

Question 1

A 32-year-old man comes to the physician for a follow-up examination 1 week after being admitted to the hospital for oral candidiasis and esophagitis. His CD4+ T lymphocyte count is 180 cells/μL. An HIV antibody test is positive. Genotypic resistance assay shows the virus to be susceptible to all antiretroviral therapy regimens and therapy with dolutegravir, tenofovir, and emtricitabine is initiated. Which of the following sets of laboratory findings would be most likely on follow-up evaluation 3 months later?
 $$$ CD4 +/CD8 ratio %%% HIV RNA %%% HIV antibody test $$$

Accepted Answer

↑ ↓ positive

Answer

↓ ↓ negative

Answer

↑ ↑ negative

Answer

↓ ↑ negative

Answer

↓ ↑ positive

Question 2

A 45-year-old man comes to the emergency department with fever, nonproductive cough, and difficulty breathing. Three years ago, he underwent lung transplantation. A CT scan of the chest shows diffuse bilateral ground-glass opacities. Pathologic examination of a transbronchial lung biopsy specimen shows several large cells containing intranuclear inclusions with a clear halo. Treatment with ganciclovir fails to improve his symptoms. He is subsequently treated successfully with another medication. This drug does not require activation by viral kinases and also has known in-vitro activity against HIV and HBV. The patient was most likely treated with which of the following drugs?

Accepted Answer

Foscarnet

Answer

Lamivudine

Answer

Elvitegravir

Answer

Zanamivir

Answer

Acyclovir

Question 3

During an experiment conducted to alter the infectivity of common viruses that affect humans, an investigator successfully increases the host range of human immunodeficiency virus (HIV). The new strain of the virus can infect fibroblast-like cells in addition to the usual target of HIV. Which of the following is the most likely explanation for the increase in the host range of the virus?

Accepted Answer

Mutation of the gene coding for viral surface glycoproteins

Answer

Reassortment of genetic material between segments of two viruses

Answer

Increased rate of budding out of host cells

Answer

Excessive activity of viral RNA polymerase

Answer

Point mutations in the hemagglutinin gene

Question 4

A 60-year-old man comes to the physician’s office with jaundice. Liver ultrasound reveals a shrunken liver and biopsy reveals cirrhosis. Hepatitis serologies are below:

Anti-HAV: negative
HBsAg: negative
HBsAb: positive
HBeAg: negative
Anti-HBe: negative
Anti-HBc: negative
Anti-HCV: positive

The hepatitis C viral load is 1,000,000 copies/mL. The patient is started on an antiviral regimen including sofosbuvir. What is the mechanism of action of this drug?

Accepted Answer

Inhibits RNA-dependent RNA polymerase

Answer

Inhibits reverse transcriptase

Answer

Inhibits integrase

Answer

Inhibits synthesis of DNA-dependent DNA polymerase

Answer

Inhibits hepatitis C protease

Question 5

A 40-year-old man presents with problems with his vision. He says he has been experiencing blurred vision and floaters in his left eye for the past few days. He denies any ocular pain, fever, or headaches. Past medical history is significant for HIV infection a few years ago, for which he is noncompliant with his antiretroviral medications and his most recent CD4 count was 100 cells/mm3. His temperature is 36.5°C (97.7°F), the blood pressure is 110/89 mm Hg, the pulse rate is 70/min, and the respiratory rate is 14/min. Ocular exam reveals a decreased vision in the left eye, and a funduscopic examination is shown in the image. The patient is admitted and immediately started on intravenous ganciclovir. A few days after admission he is still complaining of blurry vision and floaters, so he is switched to a different medication. Inhibition of which of the following processes best describes the mechanism of action of the newly added medication?

Accepted Answer

Nucleic acid synthesis

Answer

Protein synthesis

Answer

Progeny virus release

Answer

Viral penetration into host cells

Answer

Viral uncoating

Question 6

A research group wants to assess the safety and toxicity profile of a new drug. A clinical trial is conducted with 20 volunteers to estimate the maximum tolerated dose and monitor the apparent toxicity of the drug. The study design is best described as which of the following phases of a clinical trial?

Accepted Answer

Phase I

Answer

Phase 0

Answer

Phase III

Answer

Phase V

Answer

Phase II

Question 7

A 49-year-old woman presents to her primary care doctor in late December with malaise. She reports worsening fatigue, myalgias, headache, and malaise that started 1 day ago. She works as a lunch lady at an elementary school. Her past medical history is notable for a distal radius fracture after a fall 2 years ago, but she is otherwise healthy and takes no medications. She does not smoke or drink alcohol. She is married and has 3 adult children who are healthy. Her temperature is 102.9°F (39.4°C), blood pressure is 101/61 mmHg, pulse is 112/min, and respirations are 21/min. On exam, she appears lethargic and uncomfortable but is able to answer questions appropriately. Breath sounds are normal bilaterally. She is started on intravenous fluids and a pharmacologic agent for treatment. Which of the following is the most likely mechanism of action of the drug being used to treat this patient?

Accepted Answer

Neuraminidase inhibitor

Answer

Reverse transcriptase inhibitor

Answer

RNA-dependent polymerase inhibitor

Answer

DNA polymerase inhibitor

Answer

Protease inhibitor

Question 8

A 44-year-old man comes to the physician for a follow-up examination. Eight months ago, he was diagnosed with HIV infection and combined antiretroviral treatment was begun. He feels well. He does not smoke or drink alcohol. Current medications include lamivudine, zidovudine, atazanavir, and trimethoprim-sulfamethoxazole. Laboratory studies show:
Hemoglobin 11.2 g/dL
Mean corpuscular volume 102 μm3
Leukocyte count 2,600/mm3
Segmented neutrophils 38%
Lymphocytes 54%
Platelet count 150,000/mm3
Serum
Folate normal
Lactate 6.0 mEq/L (N = 0.5–2.2)
Arterial blood gas analysis on room air shows:
pH 7.34
pCO2 55 mm Hg
pO2 99 mmHg
HCO3- 14 mEq/L
The drug most likely responsible for this patient's current laboratory findings belongs to which of the following classes of drugs?

Accepted Answer

Nucleoside reverse transcriptase inhibitor

Answer

Entry inhibitor

Answer

Dihydrofolate reductase inhibitor

Answer

Integrase inhibitor

Answer

Protease inhibitor

Question 9

A 26-year-old patient presents to your office with rhinorrhea that you believe to be viral in origin. He respectfully requests treatment with antibiotics, and he demonstrates an understanding of the risks, benefits, and alternatives to treatment. His mental status is intact, and you believe him to have full decision-making capacity. Which of the following is the best course of action?

Accepted Answer

Deny the patient's request

Answer

Refer the patient to an infectious disease specialist

Answer

Prescribe ciprofloxacin

Answer

Prescribe amoxicillin

Answer

Prescribe zidovudine

Question 10

An HIV-positive patient with a CD4+ count of 45 is receiving recommended first-line treatment for a case of cytomegalovirus retinitis. Coadministration with which of the following agents would be most likely to precipitate a deficiency of neutrophils in this patient?

Accepted Answer

Zidovudine

Answer

Ritonavir

Answer

Raltegravir

Answer

Foscarnet

Answer

Efavirenz

Antivirals

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HIV protease inhibitors

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