Which drug is commonly used in pre-exposure prophylaxis (PrEP) for HIV prevention?

Appeared in: AIIMS CRE 2025

Explanation

The combination of Tenofovir and Emtricitabine is the standard, FDA-approved, and WHO-recommended regimen for HIV Pre-Exposure Prophylaxis (PrEP).
Both drugs are Nucleoside/Nucleotide Reverse Transcriptase Inhibitors (NRTIs) that block the HIV reverse transcriptase enzyme.
This mechanism prevents the virus from converting its RNA into DNA, a critical step for establishing an infection.
Daily use can reduce the risk of acquiring HIV from sex by over 90% and from injection drug use by over 70%.

Option A: This was the first antiretroviral but is not used for PrEP due to its side effect profile, including macrocytic anemia and neutropenia.
Option C: This is a Non-Nucleoside Reverse Transcriptase Inhibitor (NNRTI) used for treatment, not prevention.
Option D: This NNRTI is unsuitable for PrEP due to a significant risk of severe side effects, including hepatotoxicity and serious skin reactions.

Visual 1: Diagram: HIV Replication Cycle. This visual would illustrate the specific step where Reverse Transcriptase Inhibitors (like Tenofovir and Emtricitabine) act, helping to clarify their mechanism of action.

Clinical Relevance

Nursing practice connection: Knowing Pharmacology of HIV Pre-Exposure Prophylaxis (PrEP) helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Nurses play a vital role in PrEP management, focusing on patient education about strict daily adherence, which is critical for efficacy.
Ongoing monitoring is essential, including regular HIV testing (every 3 months) to ensure the patient remains negative, as PrEP can cause drug resistance if taken by an HIV-positive individual.
Screening for renal function (creatinine) is necessary before starting and during therapy, as Tenofovir can be nephrotoxic.

How to Approach the Question

First, identify the key terms in the question: 'Pre-Exposure Prophylaxis (PrEP)' and 'HIV prevention'.
This is a pharmacology question requiring recall of a specific drug regimen for a specific indication (prophylaxis, not treatment).
Differentiate between PrEP (prevention in high-risk individuals), PEP (prevention after a potential exposure), and ART (treatment of an existing infection).
Recall the standard-of-care for PrEP, which is a specific combination of NRTIs.
Evaluate the options: eliminate drugs known primarily for treatment (Efavirenz, Nevirapine) or older drugs with less favorable side-effect profiles for prophylaxis (Zidovudine).

Concept Tested & Keywords

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