The purpose of this study is to see if an anti-HIV medication known as Stribild (elvitegravir/cobicistat/emtricitabine/tenofovir DF) is safe, tolerable and acceptable when taken for 28 days, once a day after a possible, sexual, exposure to the Human Immune Deficiency Virus (HIV).

Stribild is a combination of 1 integrase strand transfer inhibitor, 1 pharmacokinetic enhancer, and 2 nucleos(t)ide analog HIV-1 reverse transcriptase inhibitors, and was approved in August 2012, as a complete treatment regimen for HIV-1 infection in adults who are antiretroviral treatment-naïve. We are proposing to evaluate the safety, tolerability and acceptability of Stribild given to participants over age 18 after a possible sexual exposure to HIV-1. Enrolled participants will have experienced a moderate to high risk exposure, as outlined in the study protocol, within the last 72 hours - per 2005 Center for Disease Control and Prevention guidelines. Participants will take one Stribild tablet, by mouth, once a day for 28 days. Study staff will assess for changes in blood chemistries and clinical signs and symptoms from baseline health. Study participation is 90 days and will include HIV testing, STI screening, HIV/STI risk reduction counseling, clinical assessments, blood draws and surveys designed to gather knowledge and perception of HIV post-exposure prophylaxis (PEP) and HIV pre-exposure prophylaxis (PrEP). Conditional referrals to continued HIV/STI risk reduction counseling and testing will be made if risk remains high at study termination. In addition, participants will be connected to a medical provider if risk demonstrates a potential need for HIV pre-exposure prophylaxis.

Inclusion Criteria:

• > Age of 18 at time of first visit.
• HIV uninfected on the basis of a negative HIV Rapid Test
• Willing and able to provide written informed consent.
• Willing and able to provide adequate locator information.
• Willing and able to return to all study visits.
• Willing to participate in all study procedures.
• Biologic women of childbearing potential: Willing to use contraception for as long as they are on study medication plus 7 days after.
• Possible sexual exposure to HIV-1, recent enough to permit receiving the first dose of study medication within 72 hours from the end of the exposure.

possible exposure could include:

1. Unprotected anal, vaginal, oral, or mucosal (e.g. conjunctival) exposure to ejaculate from a partner who is HIV-1 infected or high risk for HIV infection and of unknown HIV-1 serostatus (may include protected sexual exposure with condom failure, breakage or slippage); or
2. Unprotected penile exposure to cervicovaginal secretions or anorectal secretions from a partner who is HIV-1 infected or high risk for HIV infection and of unknown HIV-1 serostatus (may include protected sexual exposure with condom failure, breakage or slippage)

Exclusion Criteria:

• An active psychiatric illness or active drug or alcohol abuse that, in the opinion of the investigator, could prevent compliance with study procedures.

• Pregnancy and/or Breastfeeding.

• Biologic women who are actively trying to become pregnant.

• Acute or Chronic Hepatitis B infection, by history

• Acute or Chronic Renal Disease, by history

• Creatinine Clearance at or below 70mL/min (Cockcroft-Gault equation, Actual Weight)

• Known intolerance or allergy to tenofovir DF, emtricitabine, elvitegravir or cobicistat

• Currently taking or plans to take prohibited medication while enrolled in the study.

  • Prohibited Medications*

    • Propulsid (Cisapride)
    • UroXatral (Alfuzosin)
    • Dihydroergotamine
    • Ergotamine
    • Methylergonovine
    • St John's Wort (Hypericum perforatum)
    • Altocor, Altoprev, Mevacor (Lovastatin)
    • Zocor (Simvastatin)
    • Orap (Pimozide)
    • Rifadin, Rimactane (Rifampin)
    • Viagra (Sildenafil when dosed as REVATIO)
    • Halcion (Triazolam)
    • Versed (Midazolam) (when administered orally)
    • Antiretroviral medications used to treat or prevent HIV infection.

90 days