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 Marius, how far along in your course of PEP are you? In the first few days/weeks side effects can present more heavily as your body adjusts to the medication. It would be expected to lessen as you get to the end of your course of PEP. Before starting PEP did you have only known bone/muscle/joint/kidney problems? The medications you have mentioned do rarely cause side effects associated with these body systems however this is usually in people with preexisting conditions. It would not be likely to be caused by a short term course of PEP with no predisposing factors. Even more so, if these symptoms were caused by PEP it would be expected for them to self resolve when PEP ends – there is no risk of long term side effects from a 28 day course.
If you are remaining anxious about this medication, are you able to find out the status of the woman you slept with? Determining if she is HIV negative or undetectable would eliminate any potential risk. Also, oral sex carries a very low risk of HIV transmission would would not often require PEP. Please follow this link for more information about testing and transmission: https://i-base.info/qa/factsheets/hiv-transmission-and-testing
Hi, I had a quite low risk exposure this weekend, but I decided to go on PEP anyway due to me not knowing too much about this girl. She is scandinavian and in her mid 20’s. She removed my condom while giving me oral sex, and started to insert my penis into her. I also gave her oral sex from front to the back. I have hsv downstairs, but didn’t have an outbreak at the time.
I am now more worried about bone density and kidney problems than actually getting HIV. These meds makes me feel very fatigued with muscle and joint pain. I am not sure if I can take it for the full 28 days. I have been given 2x raltegravir and 1x tenofovir. I am really worried about long term consequenses.
Thank you, sir, for the advice.
Hi Mohammed, while you are on PEP no test will be accurate. This is because PEP can effect the result by its effect on HIV. PCR testing is also not routinely used for HIV testing due to a poor accuracy and time requirements. This test is usually best in the first few weeks of a potential transmission and also experiencing symptoms. This explains more: https://i-base.info/guides/testing/appendix-1-different-types-of-hiv-test
A 4th generation antigen/antibody test and widely used in health clinics. These tests are accurate from 6 weeks after finishing PEP.
According to the test conducted, a day after the exposure, I was negative and the girl was positive, and I started taking pep at 33 hours or less than 33 hours after the exposure. And I am still taking my pep, I am in my 15th day’s course of the pep and I am worried to know my status. Would the PCR test reveal my status at this point?
Hi Junior, what were you taking in the 3 days before starting Trisbuss? If this was another medication used to prevent HIV transmission your risk is very small. You initially started PEP (post-exposure prophylaxis) within 72 hours of the exposure and have been given a full course to take. Your risk is also reduced by the type of sex which is explained more here: https://i-base.info/guides/testing/risks-for-transmission
Continuing with your medication means there is a very small to 0 risk of transmission.
Hello. I had sex with a girl and condom broke I notice after I jacked 3x then pull out immediately so I decided to test her with determine kit… It came out positive so I decided to go see the doctor the doctor gave me some pills that was after 24 hours which I took for 3 days and after that I been on tribuss pills for 30 days since then and this is my 18th day of been on tribuss. So am i at risk
Hi Chris, how is this girl doing? Using a condom is effective at preventing HIV. There is no risk to you.
Hello, i had a Sex with a Girl, on pulling out ị noticed some Blood stains on the Condom but the Condom wasn’t broken nor tore, i quickly Tested her with determine kit.. It showed positive double lines(though its not confirmatory).. Ị ve placed myself on PEP Medication within 24 hours.. So am ị at Risk?
Hi Mohamed, was this test of the woman or yourself? Testing only a day after an exposure is not going to give an accurate result – there is no time for any test to pick anything up. Are you still taking PEP? It would make sense to continue with your course of PEP if you still have access to it. You can then test 6 weeks after the course of PEP ends.