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 Ralph,
Please see the above post.
Thank you doctor for your response. My last question l was exposed to a person who is hiv positive on a Saturday evening around 7pm and started pep on Monday around 1pm.
1) Was my timing for pep good enough?
2) this was my first time getting exposed to a person who is Hiv positive. And the sex less than 2 minutes? What are the chances of contracting the virus when exposed for the first time?
Hi Ralph,
This could be a minor side effect of the PEP or something else. If it’s a problem there’s medication that you can take. If it last for more than 48hrs please see a doctor.
I just started taking PEP, after an hour or two l had diarrhea.
Hi Mutumna,
PEP needs to be taken within a maximum of 72 hrs after exposure. Therefore, there’s no reason for you to take it. What you will need to do is test. Please see Q1 here:
http://i-base.info/qa/what-are-the-most-asked-questions
Is PEP effective 85hrs after exposure?
Hi Gary,
Thanks for sharing with us your story.
I hope it all goes well.
Jorge…
It’s great that you started PEP within 3 days! The earlier the better.
30 days ago after having sex with a man I had been with once before I found out that the condom had broken or he had broken the condom during sex! I freaked out because I knew that I had his semen in me.
I don’t want to paint ugly pictures here, but after sex I went to the bathroom and his cum came out of me. As I was heading out of the bathroom I saw the used condom laying on top of the trash can and it was broken. I’ll never know for certain if he did it on purpose or not, but I knew his cum was in me.
We had discussed safe sex before hand, and he had told me he was negative. But I felt he broke the condom on purpose, and the only reason I know to do that is to convert someone.
I drove as fast as I could to the AIDS clinic and told them what happened. The ran tests on me and prescribed PEP. Thankfully there was a program to help pay for all of this as the cost of the blood work and drugs was a total of $3700.00.
I tested negative that day, and ended the PEP two days ago…I went for my 30 day test today…negative again. I am happy and relieved, but you or I neither one will be certain for another 90 days!
I know in my heart that I am negative, it was only one time, he swears that he’s negative and even waived papers in my face to prove it because he thought I was going to harm him, but I didn’t want to take any chances!
I’m sure we’ve both learned lessons from this, but I don’t care if it pisses a guy off or not…I always discuss HIV status, state that safer sex is necessary, and now I will take breaks in the action to see and feel the condom.
I haven’t made it to this age without being careful and selective. You need to take charge Jorge, if you’re a sexually active man, you need to be the one who is in charge of your safety, not someone else.
The positive man who bred you is not the type of person you want to have sex with. I don’t care about all the people taking PREP, it isn’t the main protection, it’s just a second layer of protection. Ask every partner’s status, and be prepared to hear lies, but it doesn’t matter…use PROTECTION EVERY TIME!
Hi Jorge,
Please read the above post and the following:
http://i-base.info/pep-and-prep/
I had sex with a gay guy and I didn’t use a condom. I was so scared that I asked him if he was positive and he said that he was positive. I started PEP within 3 days of the risk. Am I OK?