Question
Do I need to restart on-demand PrEP?
4 May 2023. Related: Adherence, All topics, PrEP.
I am on on-demand PrEP. I had my last single dose on Sunday at 2pm.
If I were to start again today(Tuesday), do I need to take it at the same time, or do I take it whenever, for example, 1 dose at 4pm, and the subsequent doses to follow at 4pm on Wednesday and Thursday?
Do I also need to give 2 hours for the 1 dose to work today?
I assume it’s like 2-1-1 but since it’s less than 7 days, I will take 1-1-1?
Answer
Hi, how are you doing?
As your last dose was Sunday and you have had a gap between doses, you will need to restart on-demand PrEP.
Your first dose (Tuesday) will need to be a double dose taken 2-24 hours before sex. Then as you have mentioned you take your subsequent doses at the same time.
On-demand can become daily dosing if you continue with a single pill daily at the same time after an initial double dose. Or as you have done so, on-demand PrEP will be complete when you take a dose of PrEP each day, the following 2 days after sex.
Please see this link about on-demand dosing in this guide to PrEP.
https://i-base.info/guides/prep/on-demand
Josh.
Hello Tim,
if you are restarting on demand dosing within a day of your last dose (for example last dose Monday, next dose Wednesday) you can re-start with one or two doses.
If the time between your last dose and re-starting on demand PrEP is 2 days or more (for example last dose Monday, re-start dose on Thursday) it is more important to re-start with a double dose.
Please see more information on 2:1:1 dosing in the UK guide to PrEP:
https://i-base.info/guides/prep/on-demand
Agreed, the advice above given by Josh is confusing and contradicts what is published on your website. I agree with the above poster, it says on your website that if restarting PrEP on-demand within 7 days of last medication dose, that only one loading dose is required? Not two? Please urgently clarify, with thanks.
Hi Julian, as you had taken that initial dose and only missed one day before continuing with daily PrEP you are covered.
This is explained here: https://i-base.info/guides/prep/on-demand
If you had missed more than 2 days of PrEP before restarting you would be required to start again with a double dose.
Please help
I took 2 pills on 29/12 but do not have sex. I did not take a pill on 30/12. I continued to take 1 pill on 31/12 and have sex on that day and 1/1. After that i took a pill every day until 3/1. Am i covered?
Thank you
Hi Will, thanks for you comment. I added a link in the post to this page about 2:1:1 dosing in the UK guide to PrEP:
https://i-base.info/guides/prep/on-demand
Having one day without PrEP in between two sets of on-demand dosing, probably means the second on-demand course could start with either a single or double dose. If there are two days without PrEP, then starting with a double dose is more important.
This information is based on expert advice though. It has not been formally studied as part of a study as this would not be possible.
It would be good to include an example of this situation in your main article. There is little guidance about restarting on demand dosage and this would be helpful.
Yes you can. You can follow the second stage of your dose restart time.
Thank you for clarifying that. So I’m covered and can follow the second stage of my 1 single dose restart time.
Thanks.
Hi James, I do apologise. I did make an error and thank you for pointing it out. As the gap was only Monday without PrEP you do not need to restart. This would also mean you are not limited to the time of the first dose and you can continue at 4 as you have mentioned. This is covered by the initial double dose which can allow a few days without PrEP.
Hello,
This is very confusing. Your website shows if I restart within 7 days, I will only need to restart with 1 single dose? So are you now saying information on your website is incorrect?
I was also told by another of your colleague that my dose level in my body should be more than enough. I had 2-1-1-1 from Thursday until Sunday. I start 1 single dose on Tuesday, technically only missing Monday’s single dose and had sex Tuesday evening.
I will continue 2 more single doses today and tomorrow but your answer contradicts with what the website shows and also the maximum of 7 doses in any 7 day period?????