FEATURE: The One a Day Pill to Prevent HIV


Pre Exposure Prophylaxis (PrEP) – The One a Day Pill to Prevent HIV


Eleanor Frederick, MSc, MPH

Pre-exposure prophylaxis or PrEP is an anti-HIV drug to be used as a prevention tool for people who are not infected with HIV (i.e. HIV negative), but who are at significant risk of acquiring HIV to prevent infection by taking one pill every day. This pill called Truvada, contains two medications, tenofovir and emtricitabine. The United States Public Health Service (USPHS)/CDC 2014 clinical guidelines stipulate that HIV testing and symptom history information are needed to rule out acute (recent) or chronic (prolonged) HIV infection before PrEP can be prescribed. PrEP should only be used by individuals who are HIV negative.  

To provide high-level protection the CDC states that at the start of use, PrEP needs to be taken for five to seven days for anal sex and up to three weeks for vaginal sex. It should be used in combination with other HIV prevention strategies (i.e., condoms and safer sex and injecting practices), and is not intended to be used alone to prevent the spread of HIV.

What is Prophylaxis? Prophylaxis means taking a drug or drugs before you are exposed to an organism that could cause an infection.

Pre- means before; Exposure – Means contact;           Prophylaxis – means prevention.

Example:  When planning travel to a malaria endemic region your physician may prescribe an anti-malarial drug as a prophylaxis in case you become exposed.  The antimalarial drug should be taken before the trip, taken during the trip and taken after return from the trip.

PrEP for preventing HIV works in a similar manner. In this scenario; an HIV-negative person takes PrEP daily to prevent HIV infection from an exposure before, during and after sex or sharing needles.

Tenofovir and emtricitabine (Truvada- true-VAH-duh); works in an HIV negative person to keep the virus from establishing a permanent infection.  They inhibit the life cycle.  When an HIV-negative person takes Truvada as prescribed before exposure to HIV, Truvada is already inside the immune cells.  If or when HIV gets into the cell, Truvada stops and prevent HIV from further infecting the cell and continuing its life cycle. The virus will then die without causing chronic infection.

While using Truvada, if an individual is exposed to HIV through sex or injection drug use, they must stop using Truvada which will be replaced by a three drug regimen by their healthcare provider. Failure to do so can result in resistance to Tenofovir and Emticitabine, which are also used in HIV treatment regimens.

Although HIV is a preventable disease, globally approximately 1.8 million persons became newly infected in 2016. Antigua and Barbuda reported 65 new cases of HIV infections in 2016.   According to the Director of the CDC Tom Frieden, M.D., M.P.H. “PrEP, used along with other prevention strategies, has the potential to help at-risk individuals protect themselves and reduce new HIV infections in the US.” However, PrEP is not yet available in most of the developing world. Therefore currently, we are not able to take advantage of this prevention tool in Antigua & Barbuda.

The CDC states that when PrEP is taken consistently, that is individuals are adherent to the prescribed plan of one pill every day, it has been shown to reduce the risk of HIV infection in people who are at high risk by up to 92%. PrEP is much less effective if it is not taken consistently.

PrEP is a powerful HIV prevention tool and can be combined with condoms and other prevention methods to provide even greater protection than when used alone. But people who use PrEP must commit to taking the drug every day and seeing their health care provider for follow-up every 3 months. The CDC states that “those excluded from taking PrEP are Adolescents and adults and children who are living with HIV”.

The CDC recommends that HIV-negative women who are pregnant or who are trying to become pregnant talk with their health care providers about the risks and benefits of taking Truvada for PrEP. The CDC also states that PrEP is a promising tool that women can use to prevent HIV infection without their partners’ cooperation.  In 2014, the US Public Health Service released clinical practice guidelines suggesting that health care providers now discuss PrEP as one of several options for protecting HIV-negative individuals when their partners are HIV positive (serodiscordant couples) when they are interested in getting pregnant.

Knowledge about PrEP and its availability and accessibility in the developing world is important. From 2015 to October 2017 I conducted a survey to determine whether individuals in Antigua and Barbuda were aware of PrEP, its meaning and implications for its use as an HIV prevention tool. One thousand persons were interviewed from a wide cross section of the population. The results indicated that less than 1% of those interviewed were aware of PrEP, what it means and the implications for its use as a tool for the prevention of HIV. PrEP has the potential to place HIV prevention in the control of individuals helping them protect themselves and their partners and reduce new HIV infections in Antigua and Barbuda. However, as with any medication adherence is important.

Guidelines developed by the CDC in partnership with other federal health agencies, public health experts and community leaders suggests; who are and aren’t candidates for PrEP

Candidates for PrEP: • Sexually active men who have sex with men (MSM), including African American and Latino men • sexually active heterosexual men and women at significant risk • people who use drugs (PWUD) • HIV-negative partners in mixed-status couples, including heterosexual couples seeking natural conception

Individuals may also be candidates for PrEP if they: • Engage in condomless sex • Had a recent rectal or bacterial STI • Used Post-Exposure Prophylaxis (PEP) more than once within the past year • Are women with male partners: of unknown status, who have sex with men, who have condomless sex with others, or who inject drugs • Have partner(s) with heavy alcohol or other drug use; who exchange sex for money, housing or other needs; or who have been in prison • Share drug injection equipment • Have been threatened or harmed by their partner(s) or feel controlled by them

Other individuals who may not be appropriate candidates for PrEP: • People who are HIV-positive • People who use condoms correctly and consistently and are comfortable sustaining this preventive approach • People with symptoms of recent acute HIV infection • People who intend to use PrEP only occasionally • People with kidney disease or dysfunction.

According to the PrEP continuum of care it is important to: 1. Identify individuals who are vulnerable to HIV infection, 2. Screen individuals who are eligible, 3. Refer and link PrEP-eligible candidates with PrEP providers, 4. Start PrEP regimen (medication, medical care), and 5. Retain individuals in care and adherent to PrEP regimen, 6. Stay HIV negative.

“While a vaccine or cure may one day end the HIV epidemic, PrEP is a powerful tool that has the potential to alter the course of the U.S. HIV epidemic today,” said Jonathan Mermin, of CDC. “These guidelines represent an important step toward fully realizing the promise of PrEP. We should add to this momentum, working to ensure that PrEP is used by the right people, in the right way, in the right circumstances.”



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