Pre-exposure prophylaxis: HIV prevention beyond condoms

1. Pre-exposure prophylaxis (PrEP)
2. Benefits of PrEP
3. Differences between PrEP and PEP
4. People who can benefit from PrEP
5. Considerations before starting PrEP
6. Steps in PrEP
7. Frequently asked questions

Pre-exposure prophylaxis (PrEP) is a groundbreaking HIV prevention strategy that has transformed the landscape of HIV prevention worldwide.

It involves the use of antiretroviral medications by HIV-negative individuals to reduce the risk of acquiring HIV infection.

In this post, we’ll explore the details of PrEP, its effectiveness, benefits, considerations, and how it is changing the approach to HIV prevention.

Pre-exposure prophylaxis (PrEP)

Pre-exposure prophylaxis (PrEP) is a preventive HIV treatment method that involves taking antiretroviral medications regularly before potential exposure to HIV.

The primary medication used for PrEP is a combination of tenofovir disoproxil fumarate and emtricitabine (TDF/FTC), sold under the brand name Truvada®.

It is important to note that PrEP is not a standalone HIV prevention method and should be used in combination with other preventive measures, such as condom use, regular HIV testing, and risk reduction counselling.

Additionally, PrEP does not protect against other sexually transmitted infections (STIs) or bloodborne pathogens, so individuals using PrEP should still practice safer sex and harm reduction strategies.

How PrEP works

PrEP works by blocking the replication of HIV within the body, preventing the virus from establishing a foothold and causing infection.

TDF and FTC work by inhibiting the activity of HIV reverse transcriptase, an enzyme necessary for the virus to replicate its genetic material.

By blocking this enzyme, PrEP reduces the likelihood of HIV infection, even if an individual is exposed to the virus through sexual contact or injection drug use.

Types of PrEP

There are currently two main types of PrEP formulations available:

1. Oral PrEP: Oral PrEP involves taking a daily oral medication containing a combination of two antiretroviral drugs, tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC), sold under the brand name Truvada or its generic equivalents. This form of PrEP is highly effective when taken consistently and correctly and has been approved by regulatory agencies such as the U.S. Food and Drug Administration (FDA) for use in HIV prevention.
2. Long-acting injectable PrEP: Long-acting injectable PrEP, also known as LA-PrEP, is an alternative form of PrEP that involves receiving injections of long-acting antiretroviral medications at regular intervals (e.g., every 8 weeks). One such medication, cabotegravir, has shown promise as a long-acting PrEP option in clinical trials. Cabotegravir is an integrase strand transfer inhibitor (INSTI) that is administered as a long-acting injectable suspension. It works by inhibiting HIV replication and preventing the establishment of infection in individuals at risk of HIV.

Both oral PrEP and long-acting injectable PrEP have been shown to be highly effective in reducing the risk of HIV infection when taken as prescribed.

The choice between oral PrEP and long-acting injectable PrEP depends on individual preferences, adherence, and access to healthcare services.

While oral PrEP offers the convenience of daily dosing and has been widely used for HIV prevention, long-acting injectable PrEP may be preferred by individuals who have difficulty adhering to a daily medication regimen or who prefer the convenience of less frequent dosing.

Dosage

The standard dosage for PrEP is one tablet of medication containing a combination of two antiretroviral drugs, tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC), taken orally once daily.

Each tablet contains 200 mg of emtricitabine and 300 mg of tenofovir disoproxil fumarate.

Administration

PrEP should be taken consistently and at the same time each day to maximise its effectiveness in reducing the risk of HIV infection.

The medication can be taken with or without food, depending on individual preference and tolerance.

Instructions for administration

1. Take one tablet of PrEP by mouth with a full glass of water.
2. Swallow the tablet whole; do not crush, chew, or break it.
3. If a dose is missed, take it as soon as possible, unless it is almost time for the next dose. In that case, skip the missed dose and continue with the regular dosing schedule. Do not double the dose to make up for a missed one.
4. If vomiting occurs within one hour of taking PrEP, take another tablet as soon as possible and continue with the regular dosing schedule.
5. It is essential to adhere to the prescribed dosing regimen and follow up with regular appointments with a healthcare provider for monitoring and support.
6. Individuals should continue to prioritise other HIV prevention strategies, such as condom use, regular HIV testing, and risk reduction counselling, to further reduce their risk of HIV transmission.

Effectiveness of PrEP

Numerous clinical trials and real-world studies have demonstrated the effectiveness of PrEP in reducing the risk of HIV acquisition among HIV-negative individuals.

When taken consistently as prescribed, PrEP has been shown to reduce the risk of HIV infection by over 90%.

Benefits of PrEP

1. Highly effective: PrEP is highly effective in preventing HIV transmission when taken as prescribed. It provides an additional layer of protection for individuals at high risk of HIV infection.
2. Empowerment: PrEP empowers individuals to take control of their HIV prevention strategies. It allows them to make informed decisions about their sexual health and reduces their risk of HIV acquisition.
3. Flexibility: PrEP offers flexibility in HIV prevention methods, particularly for individuals who may have difficulty consistently using other preventive measures such as condoms.
4. Peace of mind: PrEP provides peace of mind for individuals at high risk of HIV infection, allowing them to engage in sexual activity without constant fear of acquiring HIV.
5. Potential public health impact: PrEP has the potential to contribute to significant reductions in new HIV infections at the population level when scaled up and made accessible to those who need it most.

Differences between PrEP and PEP

Pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP) are two HIV prevention strategies.

Essentially, while PrEP provides continuous protection for individuals at an ongoing high risk of HIV exposure, PEP offers short-term protection following a specific exposure event.

This table provides an overview of the main differences between PrEP and PEP, focusing on aspects such as timing of administration, purpose, duration of use, effectiveness, accessibility, and target population.

People who can benefit from PrEP

PrEP is recommended for individuals at substantial risk of HIV infection, including, but not limited to:

1. Men who have sex with men (MSM)

MSM remains disproportionately affected by HIV/AIDS worldwide, with elevated rates of HIV transmission within this population.

PrEP is highly effective in reducing the risk of HIV acquisition among MSM when taken consistently and correctly, offering an essential prevention option for this community.

2. Transgender individuals

Transgender individuals face unique vulnerabilities to HIV infection, including stigma, discrimination, and barriers to accessing healthcare.

PrEP can help protect transgender individuals, particularly transgender women of colour, who experience high rates of HIV prevalence and incidence.

3. Heterosexual individuals

Heterosexual individuals with HIV-positive partners or engaging in high-risk sexual behaviours, such as condomless sex or multiple partners, can benefit from PrEP.

PrEP offers an additional layer of protection against HIV transmission, reducing the risk of infection in serodiscordant couples and individuals with heightened vulnerability.

4. People who inject drugs (PWID)

PWID faces an increased risk of HIV transmission through the sharing of needles and syringes contaminated with HIV-infected blood.

PrEP can be an effective harm reduction strategy for PWID, complementing needle exchange programmes and opioid substitution therapy in reducing HIV incidence among this population.

5. Sex workers

Sex workers often face intersecting vulnerabilities to HIV infection, including socioeconomic marginalisation, stigma, violence, and limited access to healthcare.

PrEP can empower sex workers to protect themselves from HIV transmission, offering a self-initiated prevention option that complements other risk reduction strategies.

6. Serodiscordant couples

Serodiscordant couples, where one partner is HIV-positive and the other is HIV-negative, can benefit from PrEP as part of a comprehensive prevention approach.

PrEP can provide added protection against HIV transmission within serodiscordant relationships, reducing the risk of HIV acquisition for the HIV-negative partner.

Considerations before starting PrEP

1. Adherence: Consistent adherence to the daily PrEP regimen is essential for maximising its effectiveness. Missing doses or inconsistent use may reduce its ability to prevent HIV transmission.
2. Regular testing: Individuals taking PrEP should undergo regular HIV testing, typically every three months, to ensure early detection of any breakthrough infections and to monitor overall health.
3. Side effects: PrEP is generally safe and well-tolerated, but some individuals may experience mild side effects such as nausea, headache, or gastrointestinal discomfort. These side effects usually subside over time.
4. Cost and accessibility: The cost of PrEP and its accessibility vary depending on factors such as location, healthcare coverage, and the availability of generic versions. Access to affordable PrEP remains a challenge for many individuals, particularly in resource-limited settings.

The steps in PrEP

Pre-exposure prophylaxis (PrEP) involves several steps to ensure its effectiveness in reducing the risk of HIV infection.

Here are the key steps involved in PrEP:

1. Assessment and counselling

Before starting PrEP, individuals should undergo a thorough assessment by a healthcare provider to determine their eligibility and suitability for PrEP.

This assessment may include discussions about the individual’s sexual practices, injection drug use history, medical history, current medications, and risk factors for HIV infection.

Counselling should also be provided to address any questions or concerns about PrEP, its benefits, potential side effects, and the importance of adherence to the medication regimen.

2. HIV testing

Before initiating PrEP, individuals must undergo HIV testing to confirm that they are HIV-negative.

This baseline HIV test helps ensure that PrEP is appropriate for the individual and that they are not already infected with HIV.

If the baseline HIV test result is positive, the individual will need to be referred to appropriate HIV care and treatment services rather than starting PrEP.

3. Prescription and medication initiation

Once eligibility for PrEP has been established, a healthcare provider will prescribe the appropriate PrEP medication regimen.

The most commonly prescribed PrEP regimen consists of a once-daily oral tablet containing a combination of two antiretroviral drugs, tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC), sold under the brand name Truvada or its generic equivalents.

The individual will be instructed on how to take the medication as prescribed, typically once daily, with or without food.

4. Follow-up visits and monitoring

After initiating PrEP, individuals will need to attend regular follow-up appointments with their healthcare provider for ongoing monitoring and support.

These follow-up visits may include HIV testing at regular intervals (e.g., every 3 months) to ensure that the individual remains HIV-negative while taking PrEP.

Healthcare providers will also assess adherence to the medication regimen, discuss any side effects or concerns, and provide counselling and support to help individuals stay on track with PrEP.

5. Adherence support and counselling

Adherence to the daily PrEP medication regimen is crucial for its effectiveness in reducing the risk of HIV infection.

Healthcare providers should offer adherence support and counselling to help individuals develop strategies for integrating PrEP into their daily routine and address any barriers or challenges to adherence.

This may include discussions about the importance of taking PrEP consistently, reminders to take the medication, and strategies for managing side effects or other concerns.

6. Risk reduction counselling and additional prevention measures

In addition to taking PrEP, individuals should continue to prioritise other HIV prevention strategies, such as condom use, regular HIV testing, and risk reduction counselling.

Healthcare providers should offer comprehensive risk-reduction counselling to help individuals make informed decisions about their sexual health and reduce their overall risk of HIV transmission.

This may include discussions about safer sex practices, harm reduction strategies for individuals who inject drugs, and referrals to additional prevention services or support resources as needed.

Frequently asked questions

1. What is PrEP?

PrEP stands for pre-exposure prophylaxis.

It is a preventive strategy used to reduce the risk of HIV infection in individuals who are at high risk of acquiring the virus.

PrEP involves taking a daily oral medication containing a combination of two antiretroviral drugs, tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC), to prevent HIV transmission.

2. How does PrEP work?

PrEP works by blocking the replication of HIV within the body, preventing the virus from establishing a foothold and causing infection.

The medication contains antiretroviral drugs that inhibit the activity of HIV reverse transcriptase, an enzyme necessary for the virus to replicate its genetic material.

By blocking this enzyme, PrEP reduces the likelihood of HIV infection, even if an individual is exposed to the virus.

3. Who is PrEP for?

PrEP is recommended for individuals who are at substantial risk of HIV infection, including:

1. Men who have sex with men (MSM) and engage in condomless anal intercourse.
2. Individuals in serodiscordant relationships, where one partner is HIV-positive and the other is HIV-negative,.
3. People who inject drugs and share needles or syringes.
4. Individuals with a history of sexually transmitted infections (STIs) or recent high-risk sexual behaviour.

4. How effective is PrEP?

When taken consistently and correctly, PrEP is highly effective in reducing the risk of HIV transmission.

Clinical trials have demonstrated that PrEP can reduce the risk of HIV infection by up to 99% among individuals who adhere to the medication regimen.

5. Are there any side effects of PrEP?

Like any medication, PrEP may cause side effects in some individuals.

Common side effects of PrEP may include nausea, diarrhoea, headaches, fatigue, and dizziness.

Most side effects are mild and temporary, and they typically resolve on their own within a few weeks of starting PrEP.

6. How do I start PrEP?

Before starting PrEP, individuals should undergo HIV testing to confirm that they are HIV-negative.

A healthcare provider will assess eligibility for PrEP and prescribe the appropriate medication regimen.

Regular follow-up appointments with a healthcare provider are necessary for monitoring and support while taking PrEP.

7. Does PrEP protect against other sexually transmitted infections (STIs)?

No, PrEP only protects against HIV infection and does not protect against other sexually transmitted infections (STIs) or bloodborne pathogens.

Individuals using PrEP should continue to prioritise other preventive measures, such as condom use, regular STI testing, and risk reduction counselling, to reduce their overall risk of STI transmission.

8. Is PrEP covered by insurance?

Many insurance plans cover the cost of PrEP, including medication and medical appointments.

Additionally, financial assistance programmes and patient assistance programmes may be available to help individuals afford PrEP if they do not have insurance coverage or face financial barriers.

9. How long should I take PrEP?

PrEP should be taken consistently and indefinitely for as long as the individual remains at risk of HIV infection.

Individuals should continue taking PrEP as prescribed by their healthcare provider and attend regular follow-up appointments for monitoring and support.

10. Can I stop taking PrEP if I no longer feel at risk?

Individuals should consult with their healthcare provider before discontinuing PrEP.

Even if they no longer feel at risk of HIV infection, they may still benefit from continued PrEP use, especially if their risk factors change in the future.

Healthcare providers can provide personalised guidance on when and how to safely stop PrEP based on individual health needs and risk factors.