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 Dan, taking an additional 4th dose is not going to impact how effective on-demand PrEP is.
On-demand PrEP is a safe regimen to be taken 2-1-1. When taken correctly this will be more than 99% effective. Adding a 4th dose will not increase this percentage.
I took the 2-1-1 as ordered. But want to be extra safe. Would a fourth dose of pill give any impact (considering it already passed more than 48 hours since past sexual encounter and I was the top).
Hi Mark, yes you will be okay. As the first dose of on-demand PrEP uses a double dose there is a high enough level of PrEP in your body.
Being 9 hours late on this second dose is not going to impact the efficacy of treatment. You can continue taking PrEP at the same time you had started on day one. You will then be able to complete on-demand PrEP when you want.
Hello. I am on prep on demand. I was late 9 hours for second dose. I had unprotected anal sex with a guy. Am I gonna be okay? Thanks.
Hi Mark, as you had started with the double dose on Friday, being late with this second dose is not going to impact how effective your course of PrEP is.
By continuing to take your Sunday and Monday doses at 1:45 pm PrEP will remain effective and you will be covered.
Just looking for advice , currently on demand dosing, took my first double dose at 1.45pm friday, forgot my second dose untill now 11.45pm Saturday, had sex around 6pm on Saturday, if taking my sunday dose at 1.45 and then again monday at 1.45 is that enough to cover me?
Hi Mike, thanks. Please don’t worry about this. Taking a little more PEP from the second double dose won’t do any harm. Please see this newly updated guide to PrEP.
https://i-base.info/guides/prep
Hello there. I have a question. I took my first double dose at 11am. I then had sex that same day from 9 in the evening for a few hours. I took my next dose on time at 11am the next day but took a double dose by accident. We continued sez again till about 3pm. Now, the next day I set my reminder for 11am again and I was probably on autopilot and did take it but I couldn’t be sure that I did so I took another at 9pm. I then continued taking prep for the next 2 days. Is this ok?
Hi Jo, it is not clear which pills you took and missed in relation to when you had sex – especially whether or not you took the double-dose before sex. If this was the missed dose, then PEP will be more important.
It might also depend on when you previously used PrEP and if this included the previous week. i-Base are not doctorsm so perhaps you were prescribed PEP becasue the details show a higher risk or out of caution.
More info on dosing in included in the newly updated guide to PrEP:
https://i-base.info/htb/47180
Hello. I am doing on demand dosing.
I had been taking my pills correctly and had sex twice in one day and realized I had no pills left the day I had sex with two guys about 12 hours apart I did not take a dose the next day I got a refill and took a dose. They suggested I go on pep which I thought was crazy as it was just one pill missed. What is your opinion