Let’s Talk About PrEP

Dr. Kathy Oriel explains the importance and mechanics of medicines that can help prevent HIV infection.

Though it’s been decades since HIV and AIDS were considered “a gay disease,” our community continues to be affected by HIV and AIDS to a greater extent than others. As such, I wanted to provide information regarding medication now widely recommended to prevent HIV infection in certain instances: PrEP stands for pre-exposure prophylaxis, or medication taken to prevent HIV infections before a possible exposure. PEP stands for post-exposure prophylaxis or medication taken to prevent HIV infection after exposure to the virus.

First, a small caveat: Writing about this proved to be more complicated than I initially thought it would be. In discussing such issues in the office, I can look at the person before me for cues about whether my explanations make sense or have left them completely befuddled. In the office, I use medical terminology such as “receptive anal intercourse” or reflect back language the individual uses, such as top, bottom, or “getting f***ed.” The concepts of risk are complex, and having an informed discussion based on each individual’s perspective make writing an article to meet the needs of a broad audience seem daunting, but I’ll do my best.

Antiretroviral therapies (ART) are medications that inhibit the HIV virus’ ability to multiply, so decrease the levels of HIV (viral load) in the bloodstream. This, in turn, keeps the immune system healthy and, in people with HIV infection, slows or prevents progression to AIDS (acquired immunodeficiency syndrome) where the body’s immune system can no longer fight off infection.

Antiretroviral medications are grouped into six sub-types based on how each medication blocks the virus from replicating. When treating HIV, a combination of three medications from different sub-groups are used to block the virus most effectively and to prevent resistance to the medication. PrEP is a combination of emtricitabine and tenofovir, known by the brand name of Truvada®.

The Center for Disease Control (CDC) recommends that medical providers discuss daily medication to prevent HIV transmission in persons most at risk for contracting HIV:

Men who have sex with men (MSM) who have had anal sex without a condom or had a sexually transmitted infection within the past six months,

Heterosexual men or women who do not regularly use condoms during sex with partners at higher risk of HIV,

People who have injected illicit drugs in past six months and shared injection equipment,

Couples in which one partner is HIV-positive and the other is HIV-negative.

According to the CDC almost 25% of MSM qualify for use of PrEP. The CDC cites studies that show HIV transmission decreased by 90% for HIV negative persons taking PrEP.

The CDC has a terrific HIV risk calculator for those interested: cdc.gov/hivrisk/estimator.html.

This tool initially allows you to specify your sex at birth, gender identity, and HIV status. Based on that, you may then specify the risk of different sexual activities with or without a condom, with or without one partner taking HIV medications.

When I first used this tool with a patient, I was impressed that it could capture gender identity. Though ridiculously overdue, mainstream medicine has not acknowledged trans people in any real capacity. The risk reduction tool shows the chance that HIV transmission could occur with anal intercourse to either partner or vaginal intercourse to either partner. The CDC’s calculator does not include the risk for oral sex because the risk of HIV transmission is extremely low, though it is difficult to estimate exactly. Of course, the safest sex is to be in a mutually monogamous relationship with a partner who is HIV negative, and if intercourse with a penis occurs, a condom is worn every time.

The calculator also shows the number of times HIV will be transmitted for every 10,000 sexual acts. In the example above, the risk for the person who is HIV negative and having receptive anal intercourse without a condom is 138 out of 10,000 sexual acts. For each time, the risk of transmission is less than 1/10 of 1%. That’s a very small risk, but needs to be multiplied by the number of times an individual might be sexually active in one day, week, month, or year.

In order for PrEP to be effective, it should be taken every day. Even if doses are missed, it does reduce the risk of HIV transmission. PrEP is extremely safe and tends to have few side effects. The most common side effects are stomach upset and headache, but these tend to fade after the first weeks. The medication is cleared by the kidneys, and can cause issues for people with serious kidney disease.

The major downside to PrEP is price. Truvada® costs approximately $1,800 per month, and cost is essentially unchanged if the two medications are prescribed separately. Sadly, individuals without health care coverage may be the people who need PReP the most, yet it is unavailable to them because of prohibitive cost. There are medication assistance programs for PReP. My experience is that most health plans in the greater Madison area will cover PrEP with a prior authorization.

If you believe PReP might be a good idea for you, contact your physician to discuss it. It’s important that you tell them about your sexual behavior or use of intravenous drugs. Your provider will want to obtain laboratory tests, including a rapid HIV test, blood chemistries, testing for sexually transmitted infections including hepatitis, a urine test, and pregnancy test if appropriate. Initially, your doctor will want you to come back frequently, at first a month, then every three months, to see how you are doing on the medication.

What is PEP?  

PEP stands for post-exposure prophylaxis, or using HIV medications after a possible exposure to prevent HIV. PEP can be used after a healthcare provider has been exposed to HIV, after a high-risk sexual encounter, after sharing injection equipment, or after sexual assault.

The CDC recommends PEP be considered in the following situations:

Receptive and insertive vaginal or anal intercourse with a person known to be HIV-infected or whose HIV status is unknown,

Needle sharing with a source known to be
HIV-infected or HIV status is unknown,

Injuries with exposure to blood or other potentially infected fluids from a source known to be HIV-infected or HIV status is unknown (including needlesticks with a hollow-bore needle, human bites, accidents).

The most important facts to know about PEP is that it should be used as soon as possible after a possible exposure to HIV and must be used within 72 hours. Physicians will prescribe a combination of three antiretroviral medications to be taken for 28 days. The laboratory tests performed before starting PEP are the same as those with PReP. You may obtain PEP from your regular physician, an urgent care, the emergency room, or an HIV clinic.

If your provider is not experienced in prescribing PReP or PEP, there are many resources that may help guide them:

cdc.gov/hiv/guidelines/preventing.html

hivguidelines.org/prep-for-prevention/guideline/#tab_6

hivguidelines.org/pep-for-hiv-prevention/

Talk to your friends, your partners, and your healthcare providers. The more people understand about HIV prevention in regard to safer behaviors, medications for prevention, and are able to discuss sensitive topics, the healthier we will all remain.