How does PEP work?

Post-Exposure Prophylaxis (PEP) (PEP) works by using a combination of antiretroviral medicines (ARVs) to stop HIV from multiplying after a possible exposure, preventing it from establishing a permanent infection in the body. It's an emergency option taken as a daily pill for 28 days, must be started within 72 hours (3 days) of exposure for effectiveness, and works best the sooner it's started, by attacking the virus before it can spread.

How many days does it take for PEP to work?

To work, PEP must be taken within 72 hours (three days), and should be taken as soon as possible, ideally within 24 hours. PEP is not a 'morning after pill' for HIV, and it's not guaranteed to work. It's meant as an emergency measure to be used as a last resort, such as if a condom fails during sex.

Why is PEP not effective after 72 hours?

As you started PEP after 72 hours there was no benefit to the course. It is a good sign that you have tested negative but after a course of PEP 6 weeks needs to go by before the result is conclusive. This is because PEP can prevent the natural course of HIV, impacting on the result.

How effective is PEP if taken correctly?

The exact effectiveness of PEP is difficult to measure, but observational research suggests that PEP can reduce the risk of getting HIV by more than 80%. The effectiveness is highly dependent on adherence (taking PEP every day for 28 days) and, in the case of non-occupational exposure, no additional exposures to HIV.

What happens to the body after PEP?

Key points. In the UK, the recommended PEP medications of emtricitabine/tenofovir and raltegravir are generally well tolerated by most people. Some people have short-term problems such as being sick, feeling sick, diarrhoea, and headaches. Drug interactions can happen if you take PEP with other medications.

How PEP for HIV Exposure Works

When is it too late to start PEP?

PEP should be started as soon as possible, ideally within 24 hours, and no later than 72 hours (3 days) after a potential exposure. PEP started after the 72-hour period may not prevent HIV infection. The sooner PEP is started, the more effective it is.

What are the disadvantages of PEP?

One risk of PEP is that you'll miss doses or not be able to take the medication as directed. This means the treatment might not be as effective at preventing an HIV infection. PEP can also cause side effects in some people, though they're usually mild.

Is PEP as good as PrEP?

PrEP can be more effective than PEP:

PEP isn't 100% effective, and it won't prevent future HIV infections like PrEP can. So it's important to keep protecting yourself and others from HIV while you're on PEP by using condoms or taking PrEP.

How likely is PEP to fail?

These HIV transmissions are unlikely to be due to a failure of PEP. 8 cases are considered to represent potential PEP failures. This equates to 5.2 transmissions per 1000 PEP users (0.5%).

Can I test positive while on PEP?

PEP is very effective. It can also be used many times if you need it. Very few people test positive after using PEP.

How long does a PEP usually last?

PEP is usually taken for four weeks and should be started as soon as possible after exposure to HIV.

Does PEP work 100%?

How Well Does PEP Work? PEP is effective in preventing HIV infection when it's taken correctly, but it's not 100% effective. The sooner you start PEP after a possible HIV exposure, the better.

Should I take PEP just in case?

PEP must be taken within 72 hours of exposure, but should be taken as soon as possible to maximize the chance it will work. If you believe you have been exposed to HIV and are interested in PEP, don't wait. For maximum effectiveness, PEP should be initiated as soon as possible after potential exposure to HIV.

How do you know if PEP has worked?

You'll get another HIV test 4-6 weeks after you were first exposed to HIV, and then you'll be tested again 3 months later. Depending on your situation, your healthcare provider may recommend another HIV test 6 months later. It's really important to get these follow-up tests to make sure PEP worked.

How much does PEP cost?

Depending on your pharmacy, a full course of of PEP (truvada + tivicay/isentress) costs between $600 and $2,500 without insurance.

Can I drink alcohol while on PEP?

Alcohol does not reduce how effective PEP is. The problem some people experience is alcohol causing them to forget to take PEP. This is how it reduces effectiveness. However if you remember, there is no problem consuming alcohol while on PEP.

Do I need PEP if I'm on PrEP?

People who are already using PrEP typically do not need PEP if they experience a potential HIV exposure while taking their PrEP medication as prescribed.

Is undetectable 100% safe?

Yes, for HIV transmission, "undetectable" means "untransmittable" (U=U), which is considered 100% effective at preventing sexual transmission when a person with HIV takes their antiretroviral therapy (ART) consistently to keep their viral load undetectable, with extensive research supporting this conclusion. However, it's crucial to understand this applies specifically to HIV, requires strict adherence to medication, regular testing, and doesn't negate risks for other sexually transmitted infections (STIs) or the need for other prevention methods like condoms if partners have different HIV statuses or concerns.
 

Does PEP damage your immune system?

PEP drugs are very hard on the immune system. You will need to take special care to stay healthy: plenty of sleep and lots of nutritious food will help your body fight off infection. Everyone experiences PEP side effects differently.

Is there a downside to taking PEP?

PEP can cause mild side effects including nausea, upset stomach, fatigue, and headaches. These symptoms often get better or go away completely after the first week of taking PEP. For nausea, take PEP with a snack, before bed, or try ginger candy or peppermint tea.

What is the 2 1 1 rule for PrEP?

PrEP 2-1-1 starts by taking TWO pills between 2 and 24 hours before sex. Taking the pills closer to 24 hours before sex is better but you can use PrEP 2-1-1 up to 2 hours before sex. After sex, you take ONE pill 24 hours after the first pills, and ONE pill again 24 hours after that.

Is Truvada alone enough for PEP?

Truvada alone is not the most effective medication to be used as PEP. Truvada only contains two medications instead of three meds used in PEP. Are you able to speak to a doctor? Truvada does contain some of the medication of PEP, but adding a third drug (maybe raltegravir or dolutegravir) with Truvada would be better.

What to avoid while on PEP?

What should I do after I start PEP? It is important to take your daily PEP medication and use condoms. After you've completed your 28-day course of medication, we will retest you for HIV. Other things to avoid include needle sharing, chestfeeding, donating blood, plasma, organs, tissue, or semen.

Why does PEP have to be taken within 72 hours?

When taken within 72 hours of exposure and as prescribed for 28 days, the medication is highly effective at preventing HIV infection from sex and/or needle-sharing. It must be started within 72 hours to be effective, and every hour counts.

How many hours does PEP stay in your system?

PEP is different from PrEP, a prescription medication for people at risk of exposure to prevent HIV before potential exposure. There is no firm research regarding exactly how long PEP drugs remain in the body. Experts suspect it is probably not longer than 24 to 48 hours. A 28-day PEP prescription covers one exposure.