Prep: daily or on demand?

[Guest]

Hi everyone, I have a question for you guys since my doctor appointment is far away. I'm about to receive my Prep prescription and I'm reading conflicting information about the effectiveness of Prep according to its mode of taking.

My initial idea was to go on-demand, which is 2 pills at least 2 hours before sex, then 1 the day after and another the day after that. 4 pills are reported to be enough in this case.

The confusion comes as I plan to have multiple partners in the upcoming days, so I'll rather go daily in order to avoid making mistakes with the dosage.

Now, for the daily prep I read you should build up your system with one week of pills before having sex? Is this correct? What if i wanted to start on-demand and switch to daily, like 2+1+1+1 and go on permanently with 1 a day, wouldn't this work better than waiting one week?

Thanks for your answers.

[BootmanLA]

Bear in mind that the "on demand" is an off-label, not clinically tested and approved, usage, and while it appears to work reasonably well, in many situations, there's no hard data on it (because the studies simply aren't there to back it up).

The only reason, really, to go "on demand" is when it's impossible to take daily for some other reason - cost, or bad reactions to the medication, or something like that.

Now, going with 2 pills the first day, and daily after that, is probably not a bad idea if you're going to start off having sex before the normal "wait a week" is up. It might - MIGHT - even be a good idea to take 2 pills each day that you plan to have sex, for that first week. The important thing, I would think, is that once you start, don't go off the pills at all. Take AT LEAST daily once you start. Otherwise, you're not really going on a daily dosage; you're simply repeat-dosing "on demand", which just opens up multiple possible doorways to it failing to protect completely.

[Guest]

Thanks a lot for your answer, it covers exactly what I wanted to know, very helpful. I'll bite the bullet and go for the daily plan and build up one week. I'm going the cumdump way after all. 60 euros a month, 2 a day, is a reasonable price to pay for it.

[kinkysuBB]

If you care enough to go on PrEP, I’d honestly do it properly and take one a day for a full 7 days before you start cumdumping. There’ll be plenty of opportunities to be a cumdump in 7 days time. You only need to be pozzed once and you’re poz for life. 2 a day isn’t going to harm you, but there’s no studies I’m aware of to show this can reduce the 7 days it takes to build up in your rectal tissue.

Regarding event based, it’s a while since I read the study that was based on. My understanding is it appeared to work well, but a lot of the guys enrolled in the study were having so much sex that they were taking a lot of event based PrEP. So much that it approached daily dosing in some cases. There’s solid evidence that daily PrEP works. Event based is more of a gamble, although seemingly a lot better than nothing.

[timfreo]

Event based is a lottery. Odds in your favour, but still a crap shoot

[drscorpio]

On 8/28/2020 at 7:16 PM, BootmanLA said:

Bear in mind that the "on demand" is an off-label, not clinically tested and approved, usage, and while it appears to work reasonably well, in many situations, there's no hard data on it (because the studies simply aren't there to back it up).

You are correct that it is off-label because the FDA has not approved that dosing protocol. 
While it might be correct to say there is not SUFFICIENT data to draw conclusions about On-Demand Dosing, it is demonstrably incorrect to say there is no hard data (I have linked two studies below). 
[think before following links] https://www.nejm.org/doi/full/10.1056/NEJMoa1506273?query=featured_home

[think before following links] https://www.thebodypro.com/article/on-demand-prep-effectiveness

[BootmanLA]

4 minutes ago, drscorpio said:

You are correct that it is off-label because the FDA has not approved that dosing protocol. 
While it might be correct to say there is not SUFFICIENT data to draw conclusions about On-Demand Dosing, it is demonstrably incorrect to say there is no hard data (I have linked two studies below). 
[think before following links] [think before following links] https://www.nejm.org/doi/full/10.1056/NEJMoa1506273?query=featured_home

[think before following links] [think before following links] https://www.thebodypro.com/article/on-demand-prep-effectiveness

You're correct. I should have said there is a lack of sufficient, quality data.

One of the two studies (the latter one) wasn't a double-blind study; it just put a group of guys on 2-1-1 and checked to see who became poz. I note that they started with 279 patients. Of those, nearly one-fifth changed to daily PrEP during the study (meaning they weren't really on 2-1-1). A significant number (less than 10%, but closer to that than zero) dropped out entirely from the study. Only half, as it turns out, actually used event-based PrEP for the duration. Most importantly, there's no indication that they monitored any of the patients for volume of sexual activity, or filtered by type of activity (we know, for instance, that bottoming is much riskier than topping; the study itself acknowledged that was a significant limitation on its value. 

The first study referenced looked into that a little bit better. But the median number of sex acts over a four-week period for the participants seems to be between 8 and 11, meaning the median was typically between 2 and less than 3 sex acts per week. Moreover, the study notes that many of those acts - some weeks, a full third or so - didn't involve anal intercourse without a condom, and of those that did, some participants apparently only topped.

Finally, the results are still sobering for this (better) study. Looking at the 16 people who did get HIV within the time period of the study, 2 (or one in eight) were using event-based PrEP (the others were on a placebo). That's not a 1 in 8 chance of becoming poz on event-based PrEP (just to be clear) but it's showing that it only removes some, not all, of the risk over not using PrEP at all.

I'd say that if you intend to be, or are, significantly sexually active, either with multiple partners or with someone else who may have multiple partners, daily PrEP is still the way to go if you want to avoid HIV. Overall, I'd say if you placed HIV-prevention methods on a spectrum of riskiness, event-based PrEP is closer to the "safe" end, but not as close as daily PrEP, though still well ahead of things like "pulling out" and "asking partners their status" as a sole means of prevention.

[drscorpio]

I am not going to sift back through what I read, but they estimate On-Demand provides 86% reduction in risk whereas Daily is upwards of 95%. That is a significant decrease by any standard. 

[talltop]

Does it make a difference if you’re top or bottom? 
 

I remember reading that event-based works because with the initial double dose your arse absorbs the medication quickly. If your risk is from your dick, would that work equally well? In fact (I think) event-based was only recommended for gay men rather than straight sex. For a top-only gay man, the exposure to risk isn’t too different from that of a straight man. 
 

I would rather take it event-based, but as I’m only ever top Im not so confident it would offer protection. Apart from issues with being able to plan. 

[talltop]

Just to add, I guess any scientific investigation into that would be difficult as the chances of a top getting infected are much lower to start with. And the small sample 😃

[BootmanLA]

2 hours ago, talltop said:

Does it make a difference if you’re top or bottom? 
 

I remember reading that event-based works because with the initial double dose your arse absorbs the medication quickly. If your risk is from your dick, would that work equally well? In fact (I think) event-based was only recommended for gay men rather than straight sex. For a top-only gay man, the exposure to risk isn’t too different from that of a straight man. 
 

I would rather take it event-based, but as I’m only ever top Im not so confident it would offer protection. Apart from issues with being able to plan. 

That's part of the problem with the existing studies. There's a huge difference in risk for a receptive anal sex partner and an insertive anal sex partner, and there's also a goodly range in how sexually active different people can be. It's difficult to control for those variables, even if you have completely accurate data.

And of course, you often don't. Some guys may inflate the number of times they had sex to sound more appealing. Some may, at some level, be a tad embarrassed about how much sex they're having and understate it. A guy who plays in dark rooms during the period may not actually know exactly how many partners he had or how many sex acts or how many times he was ejaculated into.

Throw in the fact that the sample sizes in the studies I've seen to date were relatively small, and I'm not sure you can get a good number by which you can say the risk has been reduced, other than that it appears to be significant, yet not as good as daily.

It seems to me that if you can tolerate daily dosing, and you can afford it, it makes far more sense. It's a hell of a lot easier to set a reminder on your cell phone, or whatever, to take your medication daily than it is to KNOW you're going to have sex within two hours (what happens when it's more spontaneous than that?) and then remember again 24 and 48 hours later.

[Leather69]

The study re 2 + 1 + 1 + 1 was a French one - Inper (or Imper) not sure about the spelling. My local std specialists are great fans... in particular for people who have kidney problems. 

[Guest]

On 9/5/2020 at 9:56 PM, BootmanLA said:

It seems to me that if you can tolerate daily dosing, and you can afford it, it makes far more sense. It's a hell of a lot easier to set a reminder on your cell phone, or whatever, to take your medication daily than it is to KNOW you're going to have sex within two hours (what happens when it's more spontaneous than that?) and then remember again 24 and 48 hours later.

I do event based as I have large stretches of drought (live in a small town, all the hot gays move to the city) and then every so often a load of sex or a party or something. It'd be easier on daily to take a pill same time every day than to remember to set an alarm for event-based pill time, remember to have the pills with you if not at home, and so on. And actually I'd estimate that 75% of the time I take PrEP before heading out in case I get some, I don't get any and needn't have taken it. 

If I know I'm going to a sex party or know that I'll have a full on weekend of sex I'll tend to start the event based PrEP early so I've already built up a few days in my system rather than just that day. 

[BBSMKR]

As some might know PrEP is free in Scotland and event based dosing is clinically approved. These are the instructions I receive....

 Event based dosing involves:
• Taking a double dose of PrEP (two pills) before having sex
• Ideally taken 24 hours before having sex, but can be effective between 2 and 48 hours
• Take a single pill 24 hours after the initial double dose and then every 24 hours until 2 days after last sex

[renovers82]

Both Truvada and Descovy are designed to be taken daily.  How was your prescription written by prescriber?  Following those directions is the safest and smartest recommendations anyone can provide.