What is the proper dosing regimen for Truvada (Emtricitabine/Tenofovir Disoproxil Fumarate) as pre-exposure prophylaxis (PrEP) to reduce the risk of acquiring Human Immunodeficiency Virus (HIV)?

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Last updated: April 24, 2025View editorial policy

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From the Guidelines

Truvada as needed, also known as PrEP 2-1-1 or on-demand PrEP, is only recommended for cisgender men who have sex with men, and involves taking two Truvada pills 2-24 hours before anticipated sexual activity, then one pill 24 hours after the first dose, and another pill 24 hours after the second dose, as supported by the 2020 recommendations of the International Antiviral Society-USA panel 1.

Key Considerations

  • The standard recommendation for most people is daily Truvada for HIV prevention, as it provides consistent protection against HIV infection.
  • The 2-1-1 method is not recommended for women, transgender men, or people who have receptive vaginal sex, as Truvada doesn't concentrate adequately in vaginal tissues with intermittent dosing.
  • The 2-1-1 method works because Truvada contains two medications (tenofovir disoproxil fumarate and emtricitabine) that block HIV replication, but they need sufficient time to reach protective levels in the body before exposure.

Important Details

  • The 2-1-1 dosing schedule requires a double dose of tenofovir disoproxil fumarate/emtricitabine taken 2 to 24 hours prior to sexual activity, a second (single) dose 24 hours later, and a final (single) dose 24 hours after that, as outlined in the 2020 recommendations 1.
  • Daily (single) doses are therefore continued until 48 hours after the last sexual contact.
  • Prescribing should be sufficient to accommodate daily dosing over the desired time interval of the prescription.

Consultation with a Healthcare Provider

  • If you're considering the 2-1-1 method, it's crucial to consult with a healthcare provider first, as daily PrEP remains the gold standard for most people seeking HIV prevention.
  • A healthcare provider can help determine the best approach for individual circumstances and ensure that the chosen method is used correctly and safely.
  • Additionally, a healthcare provider can monitor for potential side effects and adjust the treatment plan as needed, as recommended by the International Antiviral Society-USA panel 1.

From the Research

Taking Truvada as Needed to Reduce the Risk of Getting HIV

To take Truvada as needed for reducing the risk of getting HIV, it is essential to follow specific guidelines.

  • On-Demand PrEP: According to the study 2, on-demand PrEP with emtricitabine and tenofovir disoproxil can be an effective alternative to daily PrEP for men who have sex with men (MSM) and transgender women who have sex with men. The IPERGAY dosing recommendation is typically followed for on-demand PrEP.
  • Daily PrEP: Daily PrEP with emtricitabine and tenofovir disoproxil fumarate (Truvada) is also an effective method for reducing the risk of HIV infection, as shown in the study 3.
  • Adherence and Safety: Adherence to the prescribed PrEP regimen is crucial for its effectiveness. The study 2 found that participants who used PrEP daily or on-demand had low HIV-1 incidence rates, and the incidence did not differ between the two groups. The study 4 also demonstrated the safety and efficacy of emtricitabine and tenofovir alafenamide for HIV pre-exposure prophylaxis.
  • Special Considerations: For individuals with active hepatitis B, the study 5 suggests that PrEP with emtricitabine and tenofovir disoproxil fumarate can be safely provided if there is no evidence of cirrhosis or substantial transaminase elevation.
  • Alternative Formulations: The study 6 compared the efficacy and safety of emtricitabine and tenofovir alafenamide with emtricitabine and tenofovir disoproxil fumarate for HIV pre-exposure prophylaxis and found that emtricitabine and tenofovir alafenamide was non-inferior to emtricitabine and tenofovir disoproxil fumarate for HIV prevention.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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