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.
Will it be necessary or be effective to take treatment after 20 days post exposure ???
Hi Tumie, this sounds like a very low risk. In the UK it is unlikely that PEP would be recommended.
Tumie
What are the chances of contracting HIV when I removed my member immediately when I hear the condom break? Do I need to take PEP or is not neccessary?it was a minute exposure then I wash myself just after.
Regards
Hi Siphesihle, HIV is a difficult virus to catch and the PEP will have reduce the risk even further. Given you went through the trouble of taking PEP, it is good to really see whether it worked. It is good to wait 3-4 weeks before testing. Much better to know so you can stop worrying.
Hey I have recently finished my PEP medication. I have taken the medication for a month. I was exposed to unsafe sex due to condom breakage. I am really scared to get tested again because I am scared that the medication might not have worked even though I took my meds everyday same time! I am so scared. How effective are PEP meds.
Hi Johannes, you are right that PEP can be used to stop HIV after exposure. This needs to be started as soon as possible, usually within 48 hours. Different countries use different HIV drugs as PEP. If this was just one risk and you were not able to use PEP, the risk of HIV is still very small – perhaps less than 1 in 300 chance. Information about PEP is here:
http://i-base.info/guides/testing/pep-pepse-and-prep
Hello, I’d like to ask regarding the PEP. Is it lamivudine and zidovudine effective to be used or prescribed as a short term treatment to prevent someone who is recently sexually exposed not to get infected?
Hi George,
If your partner is on medication and her viral load is undetectable there’s no reason why you should be using PrEP, this is because its not possible to contract HIV when someone has an undetectable viral load. For more info, please see here:
http://i-base.info/htb/32308
PrEP can be used for longer than a month. Though PEP is only for a month.
Is there any side effect if I may continue with pep after I’ve been taking it for a month? Can it hurt my health? Been trying for a child with an HIV positive lady but we appear to have not conceived, worder if continuing for another month will be dangerous to my health
Thank you for answering but I tested that day I was negative than I took pill in 85 hours? You mean it’s not working on me