Question
I was late with my third dose of PrEP. What should I do?
30 July 2023. Related: Adherence, All topics, PrEP.
Hello. I was using prep 2-1-1. I took my double dose 2-3 hours before sexual intercourse without condom. Took my second dose right on time 24 hours later. I skipped the right time of the 3rd dose and took it 4 and half hours late. Should I use an extra one now? Or another one on the next day? Thank you
Answer
Hi, how are you doing?
No You do not need to take an extra dose.
As you had taken your first 2 doses at the correct time, being a few hours late with the last dose is not going to change how effective PrEP is.
Taking an additional dose/day is not going to help improve how well PrEP works.
PrEP remains active in the body longer than 24 hours. This can allow for being late on the third dose.
Josh.
Hi Jay, you will probably be fine. There is not data that can answer in such detail about dosing. HIV risk is generally low, PrEP is generally good, dosing is rarely exact.
What if you are approx. 12 hours late with your third dose (fourth pill) on a 2-1-1 regime?
Hi Worried, this would be considered low risk. As you were the top and your partner is on PrEP the transmission risk is low. This would not suggest you require PEP.
I had an anal sex without condom (I’m top) with a guy who was also taking the PrEP too. So I think he is probably fine, but I can’t 100% ensure whether he’s HIV-. Should I consider it was a low risk encounter or not?
Hi Worried, taking an additional tablet of PrEP is not going to add any benefit. Do you know if this was a risky exposure? As you had been taking PrEP there is still going to be some protection – some PrEP is always better than none. This means that if this was a low risk encounter, taking PEP would not be advised.
I have similar situation but I took my last dose for almost 12 hours late. Should I consider take one more tablet on the next day? Or should I consider the PEP courses?