Question
Will 2:1:1 PrEP dosing work?
29 January 2024. Related: Adherence, All topics, HIV transmission, PrEP.
Hi, I am on the 2-1-1 protocol. On Tuesday night I took 2 pills, Wednesday morning had sex, didn’t take the pills Wednesday night because to my horror I left my pills in my locker at work, I immediately took the missed dose the following morning (Thursday) and then my 3rd dose early Friday morning. How bad is this? Here’s the dosing schedule that occurred.
2 pills on Tuesday 9pm, Wednesday 9am sex, 1 pill Thursday morning 9am, Friday morning 5am.
Answer
Hi, how are you doing?
Thanks for writing out the dosing schedule: 2 pills on Tuesday 9pm, Wednesday 9am sex, 1 pill Thursday morning 9am, Friday morning 5am.
This means you were 12 hours late with PrEP?
Do you know if this was a ‘risky’ exposure e.g., HIV positive partner with high viral load, other STIs, drugs etc…?
Some PrEP is always going to be better than no PrEP and as the first dose was a double dose there is some protection afforded for longer than 24 hours.
The same level of protection cannot be guaranteed as if taken as recommended but it can still reduce the risk of HIV.
The gap of 12 hours is going to have some impact on how effective PrEP is but the initial double dose will help with this.
Josh.
Hi Lucas, as this was not a risky exposure, even if PrEP was made ineffective by the late schedule PEP still would not be recommended.
There would be more risk of negative side effects than the risk of HIV transmission. The RNA test is encouraging and having been on doxypep along with your vaccines does further reduce the risk.
I wouldn’t say it was very risky. He said he was on prep and I have reason to believe him. But all things considered I did an RNA test at the 10 day mark, which was negative. I also did doxypep for other STIs out of caution. And I have the vax for hepatitis, HPV, meningitis, and mpox.