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.
Hello, I romanced a girl and she ended up inserting my penis in her vagina, I happened to remove it immediately after a period of about 3 seconds, this happened on Fri 15th Dec 2017, I was uncircumcised by then, I tested for HIV with her on Sunday and she was Hiv + , I started PEP after 67 hours of exposure but I am not sure whether I will be safe, please help me out? Will PEP benefit me after those 67hours
Hi Clint,
As it says on this question above, guidelines don’t recommend benefit from taking PEP longer than 72 hours after condomless sex. If you start on PEP you should finish the complete course for 1 month. Then you can test after one month to see if it has worked, and then test again at 3 months to confirm that it has.
Acyclovir is used to treat herpes, so you need to take HIV meds (ARVs) for HIV.
Is it possible for you to access PrEP? It works by taking it before you have condomless sex. So taking this pill (it has two ARVs in it) will protect you against HIV. It looks like this might fit in with your schedule, so it’s worth taking time seeing if you can access it.
Hi, I am a male who had unprotected intercourse 2 days ago with a female who had tested negative on Oralquick 2 months ago. Turns out she has been quite active and I debating on doing PEP. I can see her on Tuesday and she said will take another test but that will be 96 hours. I can start PEP tomorrow but it may not be needed if she tests negative. My questions are if I start PEP can I stop if I find it’s not needed?
How much does one trust an Oralquick tests? I read they can have 7% false negatives.
Does taking acyclvoir have any effect on HIV or PEP? Should I do PEP? Thanks
Hi Max,
If you’ve been testing negative, this means that you’re negative. Your health issues should be discussed with a doctor.
hi Doctor
I slept with a girl in February last year 2017 and condom broke next morning we went to the hospital for screening I came back negative and she came back positive the doctor prescribed me PEP and injection for other STD s I started it before 20 hours and finished it well in March
since then I have been testing each and every months up to now January 2018 (11months) post exposure still testing negative with antibody tests like alere determines , uni gold and double check both comes out negative .
but.since then I have unexplained signs and symptoms like weight lose of more than 15 kg , skin rash , lose of appetite and many many
my question are
1 can I be sure that I’m hiv negative since 11 months is more than window period or I must continue to test up to 12 months due to these unexplained signs and symptoms?
2 it’s thier any documented cases where by a PEP taker patient seroconverted after 11 months due to PEP drug ?
3 if I’m hiv negative what can be the possible cause of all these unexplained signs and symptoms .
thanks doctor
max
Hi,
Is your partner on HIV meds? If he’s undetectable there is zero risk if you don’t use condoms. See more info here.
You can ask the doctor for an HIV test to find out if you’re positive too. That’s the time to talk about starting treatment.
Hey, I’ve been sleeping with my partner two months back and he didn’t told me that he’s HIV positive I just found out yesterday, so what should I do and which treatment should I take
Hi Janet,
Its not possible for anyone to say if the PEP has worked or not, this is why testing is important. PEP is however supposed to be taken daily.
Hi I was exposed to a hiv positive person and on the third day I went on pep…I was given truvada only ….I have four days left on my dose and I’ve missed the pill twice…taken it late like 4 times…please tell me if I have a chance of testing negative after one to six weeks….I’m paranoid….your response will be highly appreciated
Hi Nomvuyiseko, PEP need to be taken asap and ideally within 48 hours. It will have no effect after 20 days.