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.
Hello
Six week ago I paid protected sex with positive girl and I had wounds on My hands. After the vaginal secretions(vaginal fluids) go my wounds.
Is there any risk of being positive?
I took pep on 22hours after exposure.
It two weeks after finishing pep but I develop HIV positive symptoms or signs.But Two days I get test negative.
Is pep increasing time of window period??
Develop fatigue, headache, night sweat,sore and ulcers on my tongue,swollen glands and muscles pain and joints pain.
is this symptoms of HIV positive or still Side effects of meds I had took( Efavirenz, lamivudine and tenofivir)???
I was asking many times.you never replied ME.
Please reply ME Am so scared about those symptoms??
Thank you am waiting you answer.
Hi Missy,
I’m so sorry to hear about what has happened.
First, it sounds like you really need some support Missy. Can you go to the local sexual health clinic or your GP and talk to them about this? There should be support to help you through this difficult time. You can talk to the doctor about taking levonelle and tell them you now want to have an abortion.
But secondly your questions about PEP. There is no difference in how PEP works if he is from Jamaica. Seroconversion, if it’s going to happen, can be slowed down by PEP. That’s why everyone needs to wait a month after finishing PEP to see if it has worked.
I was sexually assaulted by my friends, friend who lives in Jamaica and only comes to England for holidays for a few month at a time. I started taking PEP 20/21 hours after the incident took place. I was wondering because he’s not from this country, will this make it more difficult for the PEP to treat?
I have noticed a few rashes on my skin since Friday, I have been taking PEP for exactly 3 weeks today (Sunday 2nd of Dec) the rash was little tiny red dots on my shoulder/back area with a small but larger mark (looks a bit like a birth mark) next to it. if you do have an infection, Does sub conversion happen whilst you’re still taking PEP or does it happen once you stop taking it?
Also, once my PEP course is done can I take a HIV test once I’m done, I have been told to wait 1 month after PEP to check but I’m so nervous and anxious I would like to take one once I’m off the PEP… what is the effectiveness of the HIV test once you’re off PEP a couple of days? Is it possible to detect anything if you are infected?
Also, I am pregnant from this incident and I took the morning after pill (Levonelle) about 14 hours after the incident took place. I am very distressed and want an abortion will this effect PEP effectiveness?
Hi Anon,
Its not really possible to say if the PEP will be working or not, this is why its important to test. If you weren’t taking the meds at the same time as the multivitamins this won’t’ be an issue. Its OK to change the time that you take your meds.
Hi,
Last week I was sexually assulted by a man who I do not know, and therefore do not know his status.
The next day, after the incident, I rushed to get the morning after pill. I was at a loss as to what to do and panicking about my mental and mostly physical health. After researching I found out about PEP.
I was able to go to A&E and take my first dose of raltegavir and emtricitibine/tenofovir within 41 hours.
I am currently on my 6th day of the PEP regimen. I am a mess and am sick with anxiety. After researching today I found out that taking multivitamins can interfere with these medications, and I have been taking multivitamins at night for the past five days. Will that have stopped PEP from working? Also, I have changed the time I take PEP from 9pm to 8:45pm. Will this interfere with the effectiveness of PEP?
Please, if you could give me any advice or let me know about whether you think PEP will work for me I would be incredibly grateful for your help and insight.
Hi Abey,
After 48 hours PEP is less effective. What happened when you had sex last Friday? You could have a look at this picture for risks for transmission.
hey plaese assiat i have sex friday can a take it
Hi Respo,
It’s good that you tested negative 2 weeks after finishing PEP. But you usually have to wait 4 weeks for an HIV test to see if PEP has worked.
You don’t sound well at all. It’s a good idea to see the doctor. You can ask about your symptoms and find out what’s causing them.
Hey
I was on pep two week ago after finish pep I tested negative.
then from now develop some symptoms I don’t know if it HIV positive sign.including:my mouth sore and sore and ulcers on my tongue, swelling nodes or lymph nodes on my neck, headache, dry cough, muscle aches and Pain joints.
those symptoms like I am HIV positive.
is pep symptoms or side effect still now?
Please please help ME am so scare.
I am sorry for my English and please help me am so scared
Hi Ola,
If both people are HIV negative there’s absolutely no chance of HIV transmission. So there’s no need for PEP.