HIV and opportunistic infections: antiretroviral strategies MCQs With Answer

Introduction

This MCQ set on HIV and opportunistic infections: antiretroviral strategies is designed for M.Pharm students preparing for Pharmacotherapeutics II (MPP 202T). It focuses on mechanisms of antiretroviral drug classes, pharmacokinetics, drug–drug interactions, resistance, regimen selection, and management of common opportunistic infections and prophylaxis. Questions emphasize clinical and pharmaceutical implications—drug selection in co-infections (TB, HBV), safety in pregnancy, therapeutic drug monitoring, boosting strategies, and newer long-acting agents. Designed to deepen understanding beyond basics, these MCQs will help you integrate pharmacology, therapeutics, and clinical decision-making essential for advanced practice in antiretroviral therapy.

Q1. Which of the following best describes the primary mechanism of action of nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs)?

• They act as competitive substrates that cause DNA chain termination due to lack of a 3′-hydroxyl group after incorporation by reverse transcriptase.
• They bind an allosteric pocket on reverse transcriptase to inhibit enzyme activity without incorporation into DNA.
• They block the integration of viral DNA into host genome by inhibiting strand transfer.
• They prevent proteolytic cleavage of Gag-Pol polyproteins, producing immature noninfectious virions.

Correct Answer: They act as competitive substrates that cause DNA chain termination due to lack of a 3′-hydroxyl group after incorporation by reverse transcriptase.

Q2. Which statement is true regarding ritonavir when used in contemporary antiretroviral regimens?

• Ritonavir is used primarily for its potent antiviral activity against HIV reverse transcriptase.
• Ritonavir acts as a pharmacokinetic booster by inhibiting CYP3A4, increasing plasma concentrations of co-administered protease inhibitors.
• Ritonavir induces CYP3A4, reducing levels of co-administered drugs metabolized by this enzyme.
• Ritonavir is a CCR5 coreceptor antagonist requiring tropism testing before use.

Correct Answer: Ritonavir acts as a pharmacokinetic booster by inhibiting CYP3A4, increasing plasma concentrations of co-administered protease inhibitors.

Q3. Which antiretroviral class binds the reverse transcriptase enzyme at an allosteric site and does not require phosphorylation to be active?

• Nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs)
• Non-nucleoside reverse transcriptase inhibitors (NNRTIs)
• Integrase strand transfer inhibitors (INSTIs)
• Protease inhibitors (PIs)

Correct Answer: Non-nucleoside reverse transcriptase inhibitors (NNRTIs)

Q4. Which of the following antiretroviral agents requires HLA-B*5701 screening prior to use due to risk of a potentially fatal hypersensitivity reaction?

• Abacavir
• Tenofovir disoproxil fumarate
• Emtricitabine
• Lamivudine

Correct Answer: Abacavir

Q5. Which choice correctly contrasts tenofovir alafenamide (TAF) with tenofovir disoproxil fumarate (TDF)?

• TAF yields higher plasma tenofovir concentrations and greater renal toxicity than TDF.
• TAF achieves higher intracellular active metabolite levels with lower plasma exposure, reducing renal and bone toxicity compared with TDF.
• TDF is administered as an intracellular prodrug requiring lower dosing than TAF.
• TAF is contraindicated in patients co-infected with hepatitis B virus (HBV).

Correct Answer: TAF achieves higher intracellular active metabolite levels with lower plasma exposure, reducing renal and bone toxicity compared with TDF.

Q6. Maraviroc requires which of the following tests before initiating therapy?

• Baseline genotypic resistance testing for reverse transcriptase mutations
• Tropism assay to confirm CCR5-tropic virus
• HLA-B*5701 testing
• Baseline CD4 count below 200 cells/mm3

Correct Answer: Tropism assay to confirm CCR5-tropic virus

Q7. A patient on dolutegravir and rifampicin for concomitant tuberculosis requires which management strategy?

• Continue dolutegravir 50 mg once daily without change.
• Increase dolutegravir to 50 mg twice daily while on rifampicin.
• Stop dolutegravir and switch to efavirenz without dose adjustment.
• Add ritonavir to reverse rifampicin induction of CYP3A4.

Correct Answer: Increase dolutegravir to 50 mg twice daily while on rifampicin.

Q8. Which antiretroviral class has the highest genetic barrier to resistance, exemplified by agents such as dolutegravir and bictegravir?

• Non-nucleoside reverse transcriptase inhibitors (NNRTIs)
• Integrase strand transfer inhibitors (INSTIs)
• Nucleoside reverse transcriptase inhibitors (NRTIs)
• Fusion inhibitors

Correct Answer: Integrase strand transfer inhibitors (INSTIs)

Q9. In a patient with HIV and active cryptococcal meningitis, when is antiretroviral therapy (ART) initiation generally recommended?

• Immediately at the time of cryptococcal diagnosis to rapidly restore immunity.
• Deferred for approximately 4–6 weeks after starting effective antifungal therapy to reduce the risk of IRIS.
• Only after cerebrospinal fluid (CSF) cultures are negative for Cryptococcus.
• ART should be withheld indefinitely until cryptococcal antigen becomes negative.

Correct Answer: Deferred for approximately 4–6 weeks after starting effective antifungal therapy to reduce the risk of IRIS.

Q10. Which prophylactic therapy is recommended to prevent Pneumocystis jirovecii pneumonia (PCP) in patients with HIV when CD4 count falls below 200 cells/mm3?

• Azithromycin single weekly dose
• Trimethoprim–sulfamethoxazole (TMP–SMX) daily or thrice-weekly
• Fluconazole prophylaxis
• Isoniazid preventive therapy

Correct Answer: Trimethoprim–sulfamethoxazole (TMP–SMX) daily or thrice-weekly

Q11. Which adverse effect is most characteristically associated with efavirenz therapy?

• Lactic acidosis and severe hepatotoxicity as the predominant early effect
• Prominent neuropsychiatric symptoms including vivid dreams, dizziness, and mood changes
• Marked nephrotoxicity and proximal tubular dysfunction
• Severe bone marrow suppression causing pancytopenia

Correct Answer: Prominent neuropsychiatric symptoms including vivid dreams, dizziness, and mood changes

Q12. Which statement about cobicistat is correct?

• Cobicistat is an antiviral protease inhibitor with potent anti-HIV activity.
• Cobicistat is a CYP3A inhibitor used solely to boost concentrations of other antiretrovirals and can increase serum creatinine by inhibiting tubular secretion.
• Cobicistat induces CYP3A, decreasing concentrations of co-administered drugs.
• Cobicistat must be phosphorylated intracellularly to be active against HIV.

Correct Answer: Cobicistat is a CYP3A inhibitor used solely to boost concentrations of other antiretrovirals and can increase serum creatinine by inhibiting tubular secretion.

Q13. Which of the following is the most appropriate initial action when a patient on ART has confirmed virologic failure (persistently detectable viral load >200 copies/mL) despite reported adherence?

• Immediately discontinue all antiretroviral drugs and restart the same regimen after two weeks.
• Perform genotypic resistance testing and review adherence and pharmacokinetic interactions before changing therapy.
• Switch empirically to a protease inhibitor–based regimen without additional testing.
• Add a single new agent from any class to the failing regimen without changing other drugs.

Correct Answer: Perform genotypic resistance testing and review adherence and pharmacokinetic interactions before changing therapy.

Q14. Cabotegravir plus rilpivirine long-acting injectable therapy is best suited for which patient scenario?

• Treatment-naïve patient with high baseline viral load and unknown resistance mutations.
• Virologically suppressed patient on oral ART with no history of relevant resistance and willing to adhere to injection schedule.
• Patient with documented rilpivirine resistance-associated mutations seeking salvage therapy.
• Pregnant patient in the first trimester needing initial ART.

Correct Answer: Virologically suppressed patient on oral ART with no history of relevant resistance and willing to adhere to injection schedule.

Q15. Which of the following drug–drug interactions is most concerning when co-administering with protease inhibitors boosted by ritonavir?

• Co-administration with metformin, which is renally cleared with no CYP metabolism.
• Concurrent use of simvastatin, which is metabolized by CYP3A4 and may accumulate to cause rhabdomyolysis.
• Use of levothyroxine, which is unaffected by CYP3A4 inhibition.
• Concurrent use of oral contraceptives that have no metabolic interactions with CYP enzymes.

Correct Answer: Concurrent use of simvastatin, which is metabolized by CYP3A4 and may accumulate to cause rhabdomyolysis.

Q16. In HIV/HBV coinfected patients, which antiretroviral component must be included to ensure effective activity against hepatitis B and to avoid HBV flare upon discontinuation?

• Lamivudine alone as monotherapy for HBV
• An antiretroviral containing tenofovir (TDF or TAF) plus lamivudine or emtricitabine as part of the regimen
• Use of NNRTI-only regimens
• Initiation of protease inhibitor monotherapy

Correct Answer: An antiretroviral containing tenofovir (TDF or TAF) plus lamivudine or emtricitabine as part of the regimen

Q17. Which laboratory effect is commonly seen with initiation of integrase inhibitors like dolutegravir and is important to differentiate from renal dysfunction?

• Marked increase in serum transaminases due to hepatic necrosis
• Small, nonprogressive increase in serum creatinine due to inhibition of tubular secretion without affecting glomerular filtration rate
• Severe hypokalemia requiring potassium supplementation
• Profound thrombocytopenia within days of initiation

Correct Answer: Small, nonprogressive increase in serum creatinine due to inhibition of tubular secretion without affecting glomerular filtration rate

Q18. Which prophylaxis is indicated to prevent Mycobacterium avium complex (MAC) in advanced HIV disease?

• Daily trimethoprim–sulfamethoxazole when CD4 <200 cells/mm3
• Azithromycin 1,200 mg once weekly when CD4 <50 cells/mm3 in patients not on effective ART
• Fluconazole monthly for CD4 <100 cells/mm3
• Isoniazid preventive therapy only if latent TB infection is confirmed

Correct Answer: Azithromycin 1,200 mg once weekly when CD4 <50 cells/mm3 in patients not on effective ART

Q19. Which statement accurately reflects therapeutic drug monitoring (TDM) utility in antiretroviral therapy?

• TDM is routinely required for all NRTIs due to their narrow therapeutic windows.
• TDM can be useful for boosted protease inhibitors and some NNRTIs or INSTIs in cases of drug–drug interactions, adherence concerns, or toxicity to guide dose adjustments.
• TDM is unnecessary because antiretrovirals have no clinically relevant pharmacokinetic variability.
• TDM can replace resistance testing in the evaluation of virologic failure.

Correct Answer: TDM can be useful for boosted protease inhibitors and some NNRTIs or INSTIs in cases of drug–drug interactions, adherence concerns, or toxicity to guide dose adjustments.

Q20. Genotypic resistance testing prior to initiating antiretroviral therapy is recommended primarily because:

• It predicts drug levels in plasma and helps with dose selection.
• It identifies transmitted resistance mutations that may compromise first-line regimen efficacy and guides regimen choice.
• It substitutes for baseline CD4 count and viral load testing.
• It determines patient adherence patterns over the previous months.

Correct Answer: It identifies transmitted resistance mutations that may compromise first-line regimen efficacy and guides regimen choice.

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