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.
Note: This answer was last updated in July 2021 from an original post from December 2011.
Hi El, yes PEP will still be effective. It is usually only a 28 day course. Often the additional doses are included in the packet in case you are needing them again and can use these while waiting for a new prescription.
Being late with one dose my 3 hours in your course of treatment is not going to prevent your treatment being effective.
A second exposure mid-PEP will not risk a further transmission exposure. PEP will work like PrEP for the duration of the course and you will be protected from any further exposures for the time you are taking the treatment.
PEP: https://i-base.info/qa/factsheets/pep-faq
Hi Josh. I had unprotected sex with someone who is rumored to have hiv, on day 15 of the treatment, I drank the pill 3 hours later than the usual time. Then on day 21,i fear I might have been exposed to the virus, but he didn’t ejaculated inside of me. Also I only drank 29 of the doses because the 30th dose of pill fell.. Will pep still be effective?
Hi Q, starting PEP within 72 hours of an exposure means it will be effective.
For information about testing and transmission please see here: https://i-base.info/qa/factsheets/hiv-transmission-and-testing
Hi my name is Q so I had sex with a male who said he was hiv negative but I seen a text on his phone saying hiv viral load, does this mean he is 100% got hiv after asking him several times he keeps saying he doesn’t have it.
I started taking pep 52.5 hours after contact will this still be affect and doesn’t anyone know the chances of it working properly.
Hi H, missing a single dose of PEP is not likely to change how effective your treatment is. You can continue taking PEP daily as normal and will be able to test after the course.
Pimples are very common. Missing a dose/HIV are not going to be the case of them.
Hello its me H i take PEP within six hour i dont she is positive or not i had sex with her but its not long time condom was torn so i had bad feeling so i take pep in 6 hours but i quit for one day in 8 days of pep but i continue in next day is this risk for me i got pimples in my face
Hi Unknown, please see here for more information: https://i-base.info/qa/factsheets/hiv-transmission-and-testing
Anxiety and fear around testing: https://i-base.info/guides/testing/hiv-testing-feelings-of-fear-anxiety-and-guilt
I had sex with a sex worker and during the act my condom tore. It was only vaginal sex. The girl said that she has a family and does not have HIV, agent said she was tested negative for HIV a month ago. But I did not want to go by their word and hence started PEP after 41 hours (3 meds 30 days). I am on my 5th dose.
Q: What is likelihood of getting HIV infection? How to deal with anxiety, depression and sustain for next 90 days till I take the confirmatory test.
I was on holiday in Morocco and had sex with a man once using a condom and the second time he told me he had used a condom but in the morning had told me that he had not used the condom because he didn’t like the feeling. I was so angry at this as I had specifically said I would only have sex if we used condoms as I had just had HIV test and the result was negative. I went on PEP 33 hours after exposure as I did not know he his status- he told me it was negative but after lying about the condom I was not trusting of him. The problem is that I have herpes and know that can increase the chance of contracting HIV. I have been on the PEP for 3 weeks snd 2 days and have recently had oral thrush, sore head and sickness. However I have been to hospital for dehydration so I don’t know if I have seroconverted on PEP or it is related to dehydration. I keep asking the man to tell me if he has been tested but he won’t answer and I think I’m going to really hurt myself I am so worried I want to die.
Hi L, as you have started PEP within 72 hours and remained on it daily, you have already done everything right in preventing transmission.
Even though this man has not told you his status, it is still more likely that it is negative making your risk very low. Your risk is further reduced as you have only had one exposure in which this person did not use a condom.
Transmission from one exposure is very rare. Starting PEP as soon as you did means you have reduced the risk as much as you can.
For more information about transmission please see here: https://i-base.info/qa/factsheets/hiv-transmission-and-testing