## **Core Concept**
Post-exposure prophylaxis (PEP) is an emergency medication taken after potential exposure to HIV to prevent infection. It involves a combination of antiretroviral drugs and is most effective when started promptly, ideally within 72 hours of exposure.

## **Why the Correct Answer is Right**
The correct answer involves a combination of antiretroviral drugs that are currently recommended for PEP. The preferred regimen usually includes a combination of emtricitabine (Emtriva) and tenofovir disoproxil fumarate (Viread), known as Truvada, along with a third drug, which could be either raltegravir (Isentress), dolutegravir (Tivicay), or efavirenz (Sustiva) among others. The exact combination might vary based on current guidelines, patient factors, and drug availability. However, **Truvada + Raltegravir** or **Truvada + Dolutegravir** are commonly recommended due to their efficacy and safety profile.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because it likely represents a monotherapy or an outdated combination that is not recommended for PEP due to lower efficacy and higher risk of resistance.
- **Option B:** Similarly, this option might represent an incomplete or less preferred regimen based on current guidelines, possibly lacking a key component necessary for effective PEP.
- **Option C:** This could be incorrect if it suggests a regimen that is not recommended due to side effects, lower efficacy, or potential for drug resistance.

## **Clinical Pearl / High-Yield Fact**
A crucial point to remember is that PEP should be initiated as soon as possible after exposure, ideally within 2 hours, and no more than 72 hours after the exposure. Early initiation significantly increases its effectiveness in preventing HIV infection.

## **Correct Answer:** D. **Truvada + Raltegravir**.