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 jJ, the first two weeks are likely to be the most important time for PEP to work. There are no results from studies that can say how long PEP needs to last, but this might be a research option in the future. This means that your test results are really likely to be negative when you do this in a few weeks time.
Hello, I have 1 sex encounter with a sex worker. We started with condom but I tried to removed it after a while and load it inside her. I started pep after around 36hrs but I didn’t finished it since I forgot my pep to include on my vacation, that’s only 13 days of pep. Am I still protected with pep?
Hi Emma, Acriptega contains three HIV meds and it is used both for treatment and PEP:
i-base.info/guides/124
It is okay to be an hour or two early or late without making any difference on how well PEP works,
Hello, the doc prescribed Acriptega drug as pep, is it a must to take it at exactly the same time that I took it the day before for example if took it at 9:30 at night yesterday is it a major issue if i took it at 9:10pm or at 10:00 pm the next day
Hi Gloria, even though this situation has not been studied, the risk is likely to be very low becasue the person is on ART. The PEP is likely to reduce the risk even further. It would be unusual for you to become HIV positive.
hello. i got a needle stick injury on my thumb which bled after giving an intramuscular injection to a patient. the patient has been on ART for the past one year. i started pep 9 hours after the exposure. i have not experienced any side effects but still worried about my fate. what are my chances of not contracting the virus
Hi Jessia, it is great how well your boyfriend is doing on treatment. As his viral load is below 200 it means there is no risk to you. He cannot pass on HIV via sex. You do not need to use a condom or be on PrEP yourself. For this reason you do not need to be on PEP. This is called U=U: https://i-base.info/u-equals-u/ When on treatment and with a viral load below 200, you are considered undetectable. When undetectable you are also untransmissable.
My boyfriend was diagnosed last year July 2021 and he immediately commenced hiv treatment. We never had sex prior and I was hiv negative. He did his CD4 count and viral load in January 2022 and it read viral load 30 and cd4 count of 500.
He is still on medication annd uses them judiciously but we had penetrative sex for the first time in December 2022. I was still
Scared and started PEP after 24hrs. Should I be worried?
Hi Nash, no this should not worry you. A sore throat is not a significant factor to suggest that this is HIV.
Hi. I had unprotected sex and took pep after 36hrs. Its my 14th day since I started taking pep and I have a sore throat. Should this worry me.