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 Heidi,
Please see Q1 here:
http://i-base.info/qa/what-are-the-most-asked-questions
How contagious are you being possibly exposed to HIV in the first 24hrs? If exposed in the first 24hrs and then having unprotected sex after are you infectious.
Hi Ralph,
Please see Q1 here:
http://i-base.info/qa/what-are-the-most-asked-questions
I finished taking my PEP on the 23 of last month. I then tested two weeks after PEP. I tested negative. Can I rely on the results I got?
Hi Gin,
Info about both PrEP and PEP is on our site here:
http://i-base.info/pep-and-prep/
http://i-base.info/uk-guide-to-prep/
Hi
I have been exposed to a guy whom I suspect he is hiv+ Cz after we had an(condom had burst) unprotected sex we tested and he had a faint line which disappeared after an hour or so buh since then I have been restless.after 60 hrs I had arranged and got hold of PEP but since it’s recommended that the sooner I take the more chances of it working it’s really troubling me.the guy also disappeared but which I’m not really worried because at the end I have foun something to eliminate the chances of me being infected.I’m on my 2nd week now and I am able to do my daily duties and drink my meds everyday at the same time.i knw you are not God or a magician but please give me good news on my situation or at least something to hold on to.
Pep meds are not well known in South Africa surely this would save a lot of people if we would hv known in advance.
If all goes well and I test negative after six months off pep,is it fine to take on prep because it seems like no one can be trusted especially those we put close to our hearts.
Hi Zee,
Drinking alcohol won’t have an effect with your the PEP meds. Also because your partner has an undetectable viral load the risk of transmission is close to zero. Please see here for more info:
http://i-base.info/qa-on-the-partner-study/
Hi.
I am on day 14 of my pep treatment.
My first 7 days on PEP, I experienced feeling dizzy and feeling very tired especially in the morning. Certain mornings a had a bit of nausea as well.
Currently week 2- I am not having any side sides.
I have been taking my pills at the exact time every single night.
The person who exposed me to HIV, got tested this past week and the viral load is undetectable.
I have basically been anti social the last two weeks. Haven’t been drinking alcohol.
I take the PEP at night before I go to sleep- I want to know if drinking alcohol before taking the meds will have an effect on the whole process.?
Even though my partner is undetectable , I’d rather be safe than sorry. So I want to complete the remaining 16 days. But I so desperately want to enjoy a evening drinking a few glasses of wine.
Will drinking effect my treatment?
This page has been very helpful- Thank you so much for the advice given on here. It is truly appreciated.
Hi Lin,
No PEP isn’t effective 4-5 days after a possible risk. Therefore, unless your partner has an undetectable viral load and is on treatment you will need to test.
I feel worried and it is 4 days after that I know my sex partner had have HIV positive.
Is PEP effective if I take it 4 or 5 days later.?
Thanks!