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 Eli, you are right PEP is not 100% effective. When taken correctly it is usually around 80% effective. This is true for any combination of PEP that you take. Extending the course of PEP also will not increase how effective it is. In most cases PEP will have worked or not by day 21 in the course.
Doc am Eli, I read in so many places that Acriptega (pep) isn’t 100% effective why is that so & is it fine if I take it for more than 1 month like 2 months will it improve my chances??
Hi Charles, it is still more likely that you will remain HIV negative rather than become positive. The symptoms you have mentioned are very non -specific and can be side effects of your treatment, or you may have a common illness like the cold or flu. These symptoms can also be caused by stress. There are a number of factors that change the risk of transmission and these can be found here: https://i-base.info/guides/testing/risks-for-transmission
For further information about testing and transmission please follow this link: https://i-base.info/qa/factsheets/hiv-transmission-and-testing
After PEP, you can test from 6 weeks using a 4th generation antigen/antibody test. This result will then be conclusive of your status.
Hello I’m Charles, I had unprotected sex twice (two days interval) unknown to me that she was positive to HIV. We decided to run a test to know our status and I was negative and she was positive. I started PEP (2-drugs in 1 tablet) 3 days after the second encounter. I know it was already too late to take PEP but of there was a chance I had to take it. I’m on the 17th day of my medication which I boosted the drug effectiveness with immunal boosted and blood capsules. So far I have not experienced any major symptoms of early HIV infection such as flu-like fever, swollen lymph nodes, sore throat, rash,etc. However I have had some few headaches, dizziness and fatigue symptoms which I’m not sure if it’s as a result of the side effects of PEP or HIV symptoms.
Do I have a chance of not being positive after my PEP course?
Hi Mark, no you do not need to be scared. These symptoms can either be a side effect of the Acriptega or you may have another infection e.g., cold or flu. Are you still experiencing these now? As you have not missed a dose of PEP and you started so soon after exposure, your symtpoms are not suggestive of PEP failure.
Mark
Hello doc I had sex less than 5 minutes then my, I went & performed tests after 2 hours of exposure the the results were negative, started Acriptega after 4 hrs, felt wired the first days (tiredness, fatigue, dizziness) but no vivid dreams, it’s now my 16th day since I started the Acriptega the dizzness stopped but now in between my jaw and throat feels wired, I feel a little discomfort like a swellings yet I cannot physically see or torch it & I have some chills, should I get worried yet I haven’t missed any day without taking my pills at the right time. Please need some help am scared
Hi Ali, PEP is very effective, especially if started early. It is much more likely that you will be HIV negative than positive, so please do not worry.
Hello am Ali, if I take pep as prescribed by the doc for the 30 days straight without missing any day, what are possible chances for me to still endup becoming positive after the 30 days & what would have caused it. Need some help, am on my 14th day on acriptega & am worried please help
Hi Janet, PEP is usually only given up to 72 hours, which is three days. Mot doctors do not think it hs any benefit is started later than this. PEP shoud be started as early as ppssible, hopefully within 48 hours (2 days). I am sorry if a different textsaid 4 days as this would be an error.
Hi , in your text you said “ up to 4 days “ was that an error or correct . I seated taking PEP in the fourth day and I wanted to know if it still has a chance of working.