Question
Late with the after sex on-demand PrEP dose.
5 March 2022. Related: Adherence, All topics, PrEP.
Hello for all. I started 2-1-1 prep, took 2 pills 3 hours before sex. Then I took second pill after 24 hours after sex, not 24 hours after the first 2 pills – I have delayed the second pill by 3 hours. I’m still continuing taking PrEP every day because I have sex but I am just worrying is it ok to delay the second dose by 3 hours? Thank you for reply.
Answer
Hi, how are you doing?
Being 3 hours late on the second dose is not likely to cause a problem. The initial double dose will have increased the drug levels within your body more than a single dose anyway. These drugs tend to remain at the required drug level within the body for more than 24 hours.
While it is best to take the medication as routinely as you can, being late by 3 hours is unlikely to cause you any problem. As you have now continued with daily dosing, PrEP will have remained at effective level within your body.
There is no reason to be concerned after this event,
Josh.
Hi Amad, it is good that you are planning to take PrEP for the next 2 days.
As the initial dose is a double dose, it can help account for being late with the second dose. It is still going to be able to provide some protection and will mean that having sex will be considered low risk (if any risk at all).
You do not need to be worried and you do not need to start PEP.
Hi I took Prep on demand but I was late on the second dose
-Monday 2 initial pills at 4.30 pm and I did not have sex
– Tuesday 1 pill 8.30 pm (so 4 hours late from the initial 2 pills) then I had an unprotected sex at 9.30 pm (1 hour after I took my second dose)
– I am planning to continue for the next 2 days 1 pill each on time
Should I be worried here? Will Prep still work effectively?
Hi JD, as you had taken the first and second doses at the correct times and the right amount, this course of PrEP is still going to provide some protection.
Being 3 1/2 hours late is not likely going to impact how effective this course is as PrEP can remain active in the body longer than 24 hours.
Was this a high risk exposure? This can be worked out here: https://i-base.info/guides/testing/risks-for-transmission
Being 3 1/2 hours late does mean that it cannot be guaranteed to work as well as if taken on time, however it is still going to provide significant protection and PEP is unlikely required.
Hi! I am doing on demand Prep.
– Saturday 2 pills at 10:30am
– Had unprotected sex by 4pm
– Sunday 1 pill at 10:30am
– Monday 1 pill at 2pm
I took the 3rd dose 3 1/2 hours late. Is that still fine?
Thank you in advance!
Hi Carl, was this a high risk exposure? You can work this out here: https://i-base.info/guides/testing/risks-for-transmission
As you had taken this initial double dose, there is going to be a higher level of PrEP in your body than normal. This can help account for being late with the following dose and is still going to provide some protection.
As on-demand PrEP was not taken at the recommended times for 2:1:1 dosing, the same level of protection cannot be guaranteed but depending on the baseline risk of the exposure, the PrEP you did take is likely going to provide enough protection to not require PEP.
If PEP is required, continuing with PrEP until you can obtain the full combination of PEP will help to prevent transmission.
For more information about PEP please see here: https://i-base.info/qa/factsheets/pep-faq
Hey i was late with the second dose by roughly 10 hours. Is that going to be a problem or should I seek PeP immediately?
First dose (2pills) – Wednesday 9.30am
Sex – Wednesday 6.30pm
Second dose (1 pull) – Thursday 7pm
Thank you for your help.
Hi Adriano, as you have mentioned the most likely thing is that you and your friend caught the flu.
Oral sex carries little to no risk of transmission – there has never been a documented case of transmission via this route. Saliva contains antiviral properties which ‘kill-off’ HIV before transmission.
Using a condom for receptive anal sex means there is no risk of transmission from this exposure.
Your encounters are very low to no risk at all. Even with not taking on-demand PrEP properly it will still provide some protection. It is very unlikely that you are HIV positive from the exposure that you have described.
For more information please see here: https://i-base.info/qa/factsheets/hiv-transmission-and-testing
Hi,
I didn’t do the 2-1-1 dosing correct :(, I took 2 doses around 10pm had oral sex on that same Friday night, I developed rlly bad side effects was throwing up the whole night, then I had protected receptive anal with condom on the Sunday and took the second dose right after sex at around 3pm so 31 hours later after the second, then forgot to take the third dose on the Monday and took it on the Tuesday at 6am roughly 38 hours after the second,yes completely messed it up, then I began taking the prep once everyday for about a 10 days after the encounter, i had symptoms but I came to the conclusion me and my friend caught the flu partying together as we had the same symptoms it’s been 4 weeks now and I’m getting a rash on my hands completely freaking out, what are my chances ?
Hi Mario, this is still going to provide protection. As the firs dose is a double dose it remains active in the body longer than normal and can account for being 2 hours late. As long as you continue PrEP for the 2 days after exposure, this will still work.
Hi,
I took PREP at 4pm I didn’t had sex for 24h and then I had sex the second day at 6pm so basically 26h after the 2 pills, then I was late with my 2nd dose by 2 hours but I took 2 pills again and on time with my 3rd dose .