HIV And PrEP

What is PrEP?

PrEP (pre-exposure prophylaxis) is a drug taken by HIV-negative people before sexual contact, usually with an HIV-positive person.

PrEP is not needed if an HIV-negative person has sexual contact with an HIV-positive partner, providing they are taking HIV medication and have an undetectable viral load. If viral load is undetectable, HIV cannot be transmitted.

• ‘Pre’ – means taken before the ‘exposure’, which is HIV in this case.
• ‘Prophylaxis’ – something that is done to help prevent a disease, which in this case is taking a tablet.

PrEP tablets contain tenofovir and emtricitabine which are medications commonly used to treat HIV. HIV can be transmitted through sexual as well as bloodborne contact.

How Is PrEP taken?

PrEP can be taken in two ways:

• Regularly: one tablet per day.
• On-demand or ‘event-based dosing’: two tablets are taken 2 to 24 hours before sex, followed by one tablet 24 hours after sex and another tablet 48 hours after sex.

How Effective Is PrEP?

When taken correctly and daily, PrEP is more than 99% effective at stopping HIV infection. This reduces to 96% for those who take four tablets a week, and 76% for those who take two tablets a week.

Criteria vary between countries, but generally, PrEP should be taken by an HIV-negative person who has an HIV-positive partner with a detectable viral load and sex without a condom is anticipated.

Is PrEP Widely Available?

Sexual health clinics in Scotland and Wales provide anyone at risk of HIV with free PrEP.

In England, PrEP was initially made available to 10,000 people as part of the two-year IMPACT trial. This trial ended in July 2020, and the drug was officially rolled out to England later that year.

There is also currently a PrEP trial in Northern Ireland.

What Are The Advantages Of PrEP?

• PrEP is effective at helping HIV-negative people to maintain their HIV-negative status, especially those who have an HIV-positive partner or have multiple partners whose HIV status is unknown.
• PrEP has no side effects for the vast majority of people.
• PrEP is freely available in Scotland and Wales, and England followed suit in late 2020.
• PrEP allows people to have sex without using condoms without the risk of getting infected with HIV when one person is HIV-positive.

It is worth noting that mild nausea, diarrhoea, bloating and headaches were reported by less than one in 10 people in a study in the first month of taking PrEP. However, these usually stopped after the first month.

What Are The Disadvantages Of PrEP?

• PrEP can have serious side effects on kidney function and bone health, making it unsuitable for some people who have existing bone or kidney conditions.
• Regular testing is required for those on PrEP (HIV status and kidney function tests).
• Real-world adherence is not perfect – therefore in reality, PrEP will not be as effective as the theoretical numbers at protecting against HIV infection.
• There are concerns that PrEP may deprive HIV-positive people of the drugs that they need due to competition for the drugs which are also treatments for HIV-positive people.
• PrEP may lead to a greater rate of other sexually transmitted infections (STIs) due to misconceptions that it protects against STIs as well as HIV.
• PrEP may promote drug-resistant HIV if people take PrEP without knowing they are HIV-positive or become HIV-positive when they are on a break from taking PrEP.

Interview Questions

As an aspiring medic, it is important to have awareness of PrEP and its presence within the UK as well as its relevance to those with HIV-positive partners. It could also be a good topic to bring up when answering ethics questions during your interview. An example question could be:

• Should PrEP be freely and widely available? Why or why not?

Want to try some more questions? Our Interview Question Bank which has 100+ other questions and answer guides.