**Core Concept**
The management of needle stick injuries (NSIs) from HIV-positive patients involves the use of antiretroviral medications to prevent the transmission of the virus. This approach is known as post-exposure prophylaxis (PEP). The goal of PEP is to initiate treatment as soon as possible after exposure to reduce the risk of HIV infection.

**Why the Correct Answer is Right**
The recommended regimen for PEP in adults typically consists of a combination of two nucleoside reverse transcriptase inhibitors (NRTIs) plus either a non-nucleoside reverse transcriptase inhibitor (NNRTI) or a protease inhibitor (PI). This combination has been shown to effectively reduce the risk of HIV infection in individuals exposed to the virus through NSIs. The correct answer is a combination of tenofovir (an NRTI), emtricitabine (an NRTI), and raltegravir (an integrase inhibitor), which is a more modern and effective regimen.

**Why Each Wrong Option is Incorrect**
**Option A:** Zidovudine (AZT) monotherapy is not recommended for PEP due to the high rate of resistance development and the availability of more effective combination regimens.

**Option B:** Stavudine (d4T) is an older NRTI that is less commonly used in PEP due to its toxicity profile and the availability of more effective alternatives.

**Option C:** Lamivudine (3TC) is an NRTI that can be used in combination with other medications for PEP, but it is not the best choice when combined with zidovudine (AZT) due to the risk of synergistic toxicity.

**Clinical Pearl / High-Yield Fact**
The key to effective PEP is timely initiation, ideally within 72 hours of exposure. This emphasizes the importance of prompt medical evaluation and treatment in the event of a needle stick injury.

**Correct Answer:** C. Tenofovir, emtricitabine, and raltegravir