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 Ziba,
In the UK Trenvir is not recommended for PEP. However it might be used for PEP in other countries. But Trenvir contains efavirenz which is an NNRTI. And it doesn’t work against HIV-2 unfortunately.
Can trenvir used for pep work on both hiv 1 and hiv 2 strains exposure?
Hi,
It’s recommended to start PEP sooner rather than later. This means starting within 48 hours, and you’ve done this. Some countries use Trenvir but not the UK, this is because an HIV negative person might get side effects that are strong. But you can talk to the doctor about these meds including the antibiotics.
Hi
My penis had been scared a bit from doing a handjob..minor scar..so on Sartuday 04-08-18 i had sex with this women. Around 09pm while we were foreplaying she jumped on me and fucked me with no condom. I just froze and it went on … After she was done i quickly went for a shower.. We spoke about it and she told me to not work… We had sex.. with a condom and without. ..
Next day.. in the morning i went for Pep…. i took the pill at 10am on Sunday 05-08-18
I also asked her to test and she said she didnt know that she was positive.
Am I safe? I am using Trenvir ….. I am also on antibiotics.
Hi Roggy,
Usually you have to take PEP for 28 days. This is the standard treatment. So if you have the other 21 days of PEP it’s a good idea to take it.
the use of pep for seven days only can help some on who is HIV postive exposure?
Hi Aman,
As it says above, some guidelines say starting PEP 72 hours after exposure can work. However, we don’t have resources to answer questions about risks and testing. But all frequently asked questions are answered here.
Hi, I had unprotected sex with prostituted 8 days ago, and I took HIV test result negative, and on 21/07/2018 I had sex again with same prostituted unprotected, she might be 55 years old woman, I doubt she has she has HIV or not I don’t know, should take pep tablet, please answer, thanks
Hi Rupus,
i-Base doesn’t have resources to answer questions on risk and transmission. Please read the factsheets and questions here where these frequently asked questions are answered.
Hi, i had a sex with girl 2 days ago,i used condom but problem is that i reomoved that condom and i used that again(condom) is there any chances of hiv can affect to me.i dont know whether she is hiv person or not incase she is hiv person?