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 Mark, yes this is exactly what you need to do. A double dose before, and then a single dose the following 2 days with all doses being at the same time of day.
Thanks josh, i haven’t continued on with daily dosing however if sex is planned on say tuesday (3 days after my last single dose) all i need to do is double dose again and then do 1-1 24/48 hrs after to be protected correct?
Hi Mark, yes you are still protected. After a starting on-demand with a double dose, you can miss a single dose and continue with daily dosing and remain protected.
This may seem like an obvious answer however im on demand dosing took my double dose at 8.30pm Wednesday but didn’t have sex, took my next 24hrs later incase i had sex but never, so i never took my third and final (friday) as i knew i wouldn’t have sex, so instead have taken just one today (Saturday) at 7.30am am i still protected if i was to have unprotected?
Hi Jackson, as the first dose is a double dose it means there was likely enough PrEP in your body to still protect you. As you were late with the second dose it is not guaranteed to be as effective if taken on time but some PrEP will still provide more protection than none.
Do you know if this was a ‘risky’ exposure?
Hi there!
I took a double dose of prep at 2:30pm on Sunday, had sex at 5pm Sunday, and then on Monday forgot to take my dose at 2:30pm and took it at 10:30pm Monday night (9 hours late), followed by the next dose at 2:30pm Tuesday. Am I still protected?
HI Cesare, no you should not be worried. Even an hour before, PrEP is still going be effective. Some PrEP is always better than no PrEP.
As you started with a double dose, there is still a big reduction in risk of transmission. You do not need to be on PEP.
Hi! It was my first time taking prep and I only took the double dose an hour before sex, should I be worried? Start Pep?
Hi Pablo, did you take this pill (on the fourth day) before sex?
Hi there,
I’m on event based and missed my fourth dose by about 9hours. I took a pill as soon as I remembered and had sex that day. Should I go get pep or will I be OK?