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.
Note: This answer was last updated in July 2021 from an original post from December 2011.
Hi Beauty,
PEP (you won’t have been given PrEP, as this is a preventative ARV, not once a risk has happened) needs to be taken within max 72hrs after a possible risk. As you were given ARVs after 72hrs they won’t work, so there’s no need to take them. If you think the person who you had sex with is HIV positive, if their viral load is detectable, you’re going to need to have a HIV test. If they are positive but their HIV is under control, there won’t have been any risk.
Hi, 12 weeks ago I had an encounter with a male . I took pep at 40 hours after exposure. I tested with 4th generation test 12 weeks after exposure and it negative.
All guidelines for PEP including bashh and CDC most recent guidelines say that with a 4th generation test you should test at 12 weeks after Exposure for conclusive results not 12 weeks after completion PEP. I’m curious , is testing 12 weeks after completion of PEP only for rapid and antibody only test? because the current guidelines don’t support that claim.
https://www.bashhguidelines.org/media/1027/pepse-2015.pdf
https://www.cdc.gov/hiv/pdf/programresources/cdc-hiv-npep-guidelines.pdf
An answer would be greatly appreciate.Thank you.
Hi I am Beauty
I heard unprotected sex Friday and I started iching,burning around my vulva so weekday I went to the hospital and I was given injection for stds, Thursday I rush to the doctor and now on PREP. Is it too late for me?
Hi Jaydin,
This isn’t PEP failing, it’s probably your body having a reaction, so side effects. This can happen because PEP is a very powerful type of medication. The best thing to do is to talk to your doctor.
Hi am on pep and having lots of headache and some painless skin peeling on face at day 14th
Is this normal or it’s failure
Tested for hiv and its negative
Hi Kali,
It’s good that you tested HIV negative. However, PEP has been reported as delaying infection if it is not successful at preventing it.
This means that people are recommended to wait 28 days after the end of PEP to test again for HIV, which you have done. But you need to test again after 90 days for a negative result to be confirmed.
Modern tests are accurate and effective. Please see more on testing at this link.
I had unprotected sex with a lady on 1st december 2019, my health care provided placed me on PEP (Tenofovir DF) which i took for 4 weeks(28th dec 2019). I tested for HIV on 13th January which came out negative. I want to know if i am off the woods yet
Hi Mugisha,
HIV is a very difficult virus to catch. Please see this Q&A.
But can I ask how your partner is? If she is on HIV treatment with an undetectable viral load, the HIV risk to you is zero. And HIV treatment can have important benefits to her health too.
Will really PEP work for me? To me i used a condom for the first round the lady requested I to enjacurate with in lively, then after one day I asked to test her status I found she was HIV positive. Am now on PEP but am scared!
Hi Bangi,
Unfortunately, I don’t know what this pill is. But if he was on effective HIV treatment with an undetectable viral load, the risk of transmission is zero.
But if you think you are at risk please see your doctor and ask about PEP. Please read Angelina’s answer above.