Question
PrEP question about dosing
9 April 2024. Related: All topics, PrEP.
Hello, I am a gay male. I use prep on demand. I took 2 pills on day 1 and continued with 1 pill on day 2 and another 1 pill on day 3. In total I took 4 pills. However, I did not have sex. I stopped taking the prep, now for 5 days. I want to have sex tonight. Can I restart with 1 pill, because it was so recent, or do I need to restart with 2 pills, and then continue with 1 pill every day after sex?
Thank you.
Answer
Hi there
Please see detailed info on event-based 2:1:1 dosing in this updated guide:
https://i-base.info/guides/prep
Either way, there is unlikely to be much difference whether you started with a double dose again or not. Dosing can be very flexible and levels of PrEP would have been good either way.
Hi Kiki, no this will not lead it to be less effective.
PrEP can be taken as a double dose (this is how on-demand dosing is achieved).
It isn’t recommended to be taking a double dose each day as this can increase risk of side effects, but an occasional double dose will not cause harm.
If you are having trouble remembering PrEP have you considered setting an alarm as part of your morning routine to help you remember each day?
Hi Josh,
Can taking two double doses or a triple dose make PREP less efficient? I try to stick to the schedule, but occasionally I take more than one pill a day because I’m not sure whether I have taken it or not. Can there be too much Prep in your system? I’m only aware of toxicity considerations.
Hi Help, yes you can stop daily PrEP. After the initial 4 weeks of PEP and switching to PrEP there is limited evidence on how treatment can delay seroconversion.
If sexually active it remains recommended to switch directly to PrEP from PEP to prevent further exposures, however there is some risk that this can delay accurate testing. In these cases it remains the recommendation to test every 6 weeks while on PrEP.
After stopping daily PrEP, you will have a very low risk. To confirm your status you will still need a test at 6 weeks after the last dose of PrEP but the continued treatment you have been on will not change the risk.
Hi Josh!
I’m really confused with many of the answers. I understand that prep is 2 drugs and pep is 3 drugs but they have the same formula, the only difference is that pep will add a 3rd drug. so above You answered that pep can delay seroconversion, but is prep the same? I’m on prep, I still confirm my status after 6 weeks to be exact, there is no need for a time gap between pep and prep? Can you help me clarify this issue because since using prep I haven’t had any more contact so I want to stop daily prep?
Hi Help, yes you can still test 6 weeks after the last dose of PEP.
Starting PrEP immediately after PEP is recommended. You are still able to confirm your status even while on PrEP.
More information about PEP can be found here: https://i-base.info/qa/factsheets/pep-faq
Hello !
I had a problem starting PEP. After completing PEP, I took the 4th generation test the next day and it was negative. I was instructed to use the prep right after that and I used it every day. Up to now I have not had any further exposure. So can you tell me if I can determine my condition 6 weeks after the last dose of Pep while still in prep? or when? Thank you
Hi Joey, oral sex carries little to no risk of transmission. Saliva contains antiviral properties that prevent HIV transmission via this route – there has never been a documented case.
PrEP will be effective at preventing transmission of HIV.
More information about testing and transmission can be found here: https://i-base.info/qa/factsheets/hiv-transmission-and-testing
Hi Josh,
Thank you for the reply. Yes, I performed oral sex nearly 1.5 to 2 hrs after taking prep. I have a lingering question: does the 2:1:1 dosing prevent transmission through oral sex?
Thank you
Joey
Hi Joey, to clarify you had taken a double dose and then 1.5 hours later you had sex? Meaning you were only half an hour early?
In this case you do not need to extend PrEP/seek PEP. Within 30 minutes of taking PrEP you will already be afforded most of the protection from PrEP. Having sex these 30 minutes early are not going to have a significant impact on your risk and you do not need to worry. You can complete your course of on-demand PrEP when originally planned.
Hi,
I have a question about on-demand dosing too.
I took the double dose the day I engaged in sexual activities. However, I realized there were not enough time interval between first double dose and sex (approximately 1 hour and a half). I continue dosing on the following days, now it’s nearly third day. Is there a risk? Should I extend Prep or shoud I seek PEP
Thank you!