Question
Is PEP effective if taken 48 hours after exposure?
2 July 2021. Related: All topics, PEP/PEPSE.
I paid for sex with a woman but the condom tore and I only realised after I was done. There is a high chance that she was HIV positive. I started PEP after 48 hours.
I got a PCR test done 17 days after exposure. It had a less than 20/ml (undetectable) result.
Now between 14 and 35 days after exposure I have had signs of thrush, mild red rash on my face and a couple elsewhere. But no fever or swollen lymph glands.
Can the rash and thrush be because of utter stress and obsession?
My doctor says that the PCR can be relied upon and that I am negative.
Can the PEP have reduced the viral load to less than 20/ml as I took it for 15 days before the PCR test?
Please give your expert advice. I am very anxious. Thank you.
Answer
Thank you for your question.
The risk of HIV from one broken condom is very low. If your partner had an undetectable viral load on treatment, then the risk would be zero. If they were not on treatment the risk might still be only 1 in 300 or lower.
You cannot guess someones HIV status so your assumptions might also be wrong.
You started PEP within 48 hours, so it is likely it will work.
PEP – stands for Post-Exposure Prophylaxis. It is a term used for taking HIV drugs to reduce the risk of infection. PEP usually involves taking a combination of three HIV drugs for one month. The earlier PEP is started, the more likely it will work. Ideally, this should be within a couple of hours. If this is not possible, then still the earlier the better.
Some guidelines include a two-day window to do this (i.e. within 48 hours). After this, effectiveness is much less likely. Other guidelines allow up to 3 days (i.e. within 72 hours). Sometimes this may be more for psychological benefit. For example, if someone is very stressed or traumatised.
No guidelines recommend starting PEP after 72 hours.
After finishing PEP you need to wait a 4-6 weeks before testing.
If the PEP has worked, or the person was not initially infected, this will show as a negative HIV test. The test you did 17 days after the exposure will not be accurate yet.
If the PEP has not worked, this will be shown in a positive test result. Testing 4 weeks after PEP will detect 95% of infections. Testing after six weeks will detect more than 99% of infections. This result doesn’t need to be tested again.
If PEP has not worked, serosonversion usually occurs 1-3 weeks after PEP is finished. However, only 80% of people show symptoms.
Please test 6 weeks after you finished PEP is finished. If you test any earlier, you need to take a second test 3 months later.
Viral load (PRC) tests are not approved to test for HIV. In some cases they can have a role.
Please see a doctor to talk about your symptoms he best way to confirm what is causing them is to see your doctor. He/she will be able to diagnose and treat the symptoms accordingly.
Please see this link for more information about PEP:
https://i-base.info/qa/factsheets/pep-faq
Note: This answer was last updated in July 2021 from an original post from December 2011.
Hi, please advise it been more than 72, hours since I had sex, will PEP work for me
Hi Charlie,
As Angelina says on the question above, if the PEP has not worked, this will be shown in a positive test result. Testing 4 weeks after PEP will detect 95% of infections. Testing three months after PEP will detect more than 99.99% of infections and is considered confirmation that someone is HIV negative.
Is it possible for you to talk to your doctor about your stress and anxiety?
Hello i paid for sex on sept 23 at 10pm when i was done i noticed the condom was broken, 2 hours later 23 to 24 midnight i took 1 pill of (pep) then i took another pill 12 hours later , already on day 24 , then on midnight 24 to 25 i took another pill , already on day 25 i went to a clinic and they told me pep was two pills treatment , so the told me to take now the two pills , so i was taking the 2 pills 36 hours later of my possible exposure, so officially i started the treatment on 25 of sept and finished on 22 of october, i had an appointment on the clinic on 24 or 25 of october that i didnt went , then on december 13 i went (81 days after the possible exposure ) 52 days after finishin Pep to have a hiv test and went negative
What is your recommendation i am 100% negative ? Or i have to take another test
I have been suffering from stress and anxiety since then and now i have a swollen lymp node under my armpit probably from anxiety i dont know
Hi Londi,
I’m sorry to hear this story. What country do you live in? Can you talk to the clinic about it? If so they might know of similar situations. Is your sibling on HIV treatment?
Hi i have a problem that me and mi siblings w shared the same razor while perfoming tradition where they were cutting us with one razor, unfortunately one of us is positive.i went to the clinic on day 3 then they gave me pep. My fear is that i took my first pills 2 hours later, which makes it 74 hours plzzz advice
Hi John,
Sorry, i-Base doesn’t have resources to answer questions about testing and transmission. But all frequently asked questions about this are answered here.
Hi, I had unprotected sex with someone and later on we went to test but the results were negative for both of us. I started PEP within 72hrs because am scared in case that person has HIV but its not yet showing in the system even though she told me she had tested the previous week and still agreed to go and test with me again. We did the test were they prick on your finger to collect blood. Kindly advise if am at risk of contracting HIV?
Hi Dan,
It’s good that you started PEP within 48 hours and that you tested negative after completion. However you should have another HIV test 4 weeks after completing PEP. This test detects 95% of infections.
Hi, i was exposed to HIV via sexual intercourse wid a HIV Positive person who confirm just after noticong the condom had burst, i started PEP the same day within 24hrs, i test negative after PEP completion.
What are the chances i may be positive?
Hi Solomon,
Please see Q1 here: http://i-base.info/qa/what-are-the-most-asked-questions