Question
Will taking PrEP late work with on demand dosing?
27 April 2020. Related: All topics, PrEP.
Hi, I take PrEP with on demand dosing and after having sex after my first double dose i remembered my first dose post sex on time. However, my second dose was 5h late and 3rd dose was 5h late too. Will this affect my level of protection and should i continue taking it 5h late every day?
Answer
Hi
Thanks for your question. The easy answer is that you will probably be fine.
Both the drugs in PrEP stay in your body to allow for a few hours being late with dosing.
It is better to try to take them at the right time.
The after sex doses with on demand dosing only need to be taken 24 hours and 48 hours after the first double dose. Taking an extra dose for a third day will not do any harm though.
If you are still having sex every day though, then continue taking PrEP until 24 and 48 hours after the last time you had sex.
More information on real life examples for on demand dosing.
Hi Adam, the double dose is very good at providing extra cover in case the doses after sex are a little late.
Please see this guide for info on PrEP dosing:
https://i-base.info/uk-guide-to-prep-february-2024/
Please notes that we are not doctors and speaking to a doctor is recommended if you are worried :)
Hi Everyone, I really needs you help on this!
I am taking on demand PrEP, I had my first 2 doses as schedule, and continued another dose after 24 hours as planned. Then I had sex without condom at the 3rd day. But I have forgotten to taken dose on the scheduled time, which when I found out is already 9 hours late, but I have immediately taking a pill right away.
Therefore, should I start the PEP? or just continue another does at the planned schedule should be fine?
Hi Destin, I am not sure or your question, but please see this guide for info about PrEP dosing:
https://i-base.info/uk-guide-to-prep-february-2024/
I took two pills of prep maybe a hour going into 2 before i had sex i had sex around 12:30 going into 1
Hello Marcus.
i-Base does care if you are worried about catching HIV – but our resources are too limited to answer these questions.
Instead we have posted lots of info online that answers questions about testing and risk.
The guidance right now says you need a double dose before sex and one tablet for two days after you have sex.
Please see here for more information:
https://i-base.info/uk-guide-to-prep-february-2024/
https://i-base.info/pep-and-prep/
Hello I have a question. I took my first dose of prep and two hours later I had unprotected sex as a (top). Then an hour later I took another prep pill. How much am I protected?
Hi Mark, please realise that I am not a doctor – this is important. i-Base just provides information.
This link covers everything about PrEP:
https://i-base.info/uk-guide-to-prep-february-2024/
Dosing involves doing the best you can and this is usually fine. If in doubt on 2:!:1 dsoing it is fine to take another pill of an extra day. Starting with a double dose is also okay any time, just don’t take more that seven pills in a week.
Good evening Doctor.
I did a first cycle of prep on demand in the days 20/7 (2 pills and then after 2 hours, sex); 21/7 (1 pill) ; 22/7 (1 pill). All such scheme was done correctly and on time.
I started a second cycle on 29/7; 29/7 was within 7 days from 22/7 and for this reason with only ONE pill at 17:00 , then sex, then one pill on 30/7 at 17:00; and then one pill on 31/7 at 22:00.
My concern is that i took the last pill of 31/7, 5 hours after the nominal time and that at same time the first pill of the second cycle was only one (in the past you remarked the importance of the double dose, but I followed the medical indications for multiple on demand cycles…).
Should I be worried? Thanks for helping me. Regards.
Hi James, was this a high risk exposure?
Hi there,
I took the 2 PREP tablets 12 hours before sex and took the initial 1 prep 24hrs later. I forgot to take the final prep tablet for another 48 hours. Is this an indication for PEP?