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.
I almost had unprotected sex with my boyfriend who is positive today. He couldn’t get erect but he was trying to penetrate. could I get infected from that. (his viral load is undetectable)
Hi Mana, Guidelines don’t recommend any benefit from beninning PEP after 72 hours. You can find out more about PEP here.
Hi,
Would it be worth taking the PEP 9 Days after possible exposure. My doctor seems to think it will still benefit me but i am uncertain, i also dont want to go through this whole process and symptoms for nothing. Please can someone advise me on what is best to do.
Thanks
Hi Chris,
As Angelina says on this question, ‘No guidelines recommend any benefit from taking PEP after longer than 72 hours.’ However from what you say about your experience, it’s a good idea to have a complete sexual health check at the clinic.
I had a risky sex with a 20-year-old Thai girl with unknown HIV status I met on Tinder. We had sex for approximately 6 minutes, I was drunk (very very stupid mistake) and I used a condom for about half of this time towards the end. The thing that worries me the most is that in the morning there were signs of vaginal discharge on her side of the bed (yellowish with bad smell). Since the incident occurred, more than 72 hours have already passed, from what you have already written, I conclude that it’s too late for a PEP treatment now.
Previously I had taken DNA test just out of curiosity, but now I notice it has come up with data about the CCR5 gene, closely relevant to HIV infection, where my genotype is DI (not DD unfortunately). According to another website:
If your genotype is DI then you have one copy of the CCR5 Delta32 mutation, are not resistant to HIV infection, but may have slower progression to AIDS after infection.
Hence I wanted to ask for your expertise if you think that this may help show positive effects of PEP treatment even after the 3rd day.
Kind Regards,
Chris
Hi Willis,
PEP should be started within max 72hrs after a possible risk. As you had 3 I can’t say if it will be effective.
If your partner is on medication and has an undetectable viral load you won’t be at any risk. Do you know what their viral load is?
1) I had sexual unprotected intercourse with my partner who is HIV positive on Sunday at around 6:30 Pm in the evening and then on Wednesday at almost the same time and on Thursday at midnight. I took PEP on Friday at around 7:30 pm.
Can PEP be effective since I was late by 48 hours?
Hi Eddy,
Changing your meds from morning to evening will be fine. But keep taking them at the new time. You can see more info on this question here. It’s recommended that Odimune is taken at night because of side effects.
Many people on full-time meds put them into pill boxes for the whole week. So taking the tablets out of the bottle during the day will be fine.
You went to the doctor 13 hours after you had sex. It’s recommended that you start PEP within 48 hours to help them work correctly.
Hello i had unprotected sex with someone that i don’t know her status and we had sex more than once that night,we had sex on saturday around 8pm,then on sunday around 9am i went to Dr and explain everything, then he gave me odimune and he injected me.on tuesday i changed my time of taking meds from morning to 4.50pm because i was not feeling well at work because of side effects
my questions are
1.changing the tablets from morning to evening will it have bad outcomes?
2.I took two tablets out of the bottle and wrap them with toilet paper,and put them inside panado seal plastic and put them inside the inner bag parket because i was going somewhere,i didn’t want anyone to notice, will that have any bad outcomes
3.i had sex more than once ,am sure it was 3 times that night , will the tabs still work if taken correctly ?
Hi Alex, Some doctors say that PEP can work if you start within 72 hours. But, as you mention the kind of sex you had, you can look at this chart. It shows how different factors can make sex more safe or more risky.
After finishing PEP you’ll have to wait for 28 days before testing for HIV to see if it has worked. This is because PEP can delay infection. You can see more about PEP here.