How long does it take PreP to work for Tops?

[Quincy_7]

As a top, how many days does it take before you have full protection?

[+ FrankR]

28 minutes ago, Quincy_7 said:

As a top, how many days does it take before you have full protection?

Take a look here: 

https://heymistr.com/2024/08/08/how-long-for-prep-to-work-a-comprehensive-timeline/?gad_source=1&gbraid=0AAAAAC0g6bbDURytvze5Py8M4DVvDj1p6&gclid=CjwKCAiA3ZC6BhBaEiwAeqfvyvejmZr7HIM1T1MNy1dCwP7kOLd_ogCufHIYuAbtRsHzpL8YcUPbcxoCrY8QAvD_BwE

 

In short: depends on the drug you are taking, if you are taking it as prescribed; but as a rule you get maximum protection after 3 weeks of use for the daily pill. 

Edited November 25 by FrankR

[Quincy_7]

1 hour ago, FrankR said:

Take a look here: 

https://heymistr.com/2024/08/08/how-long-for-prep-to-work-a-comprehensive-timeline/?gad_source=1&gbraid=0AAAAAC0g6bbDURytvze5Py8M4DVvDj1p6&gclid=CjwKCAiA3ZC6BhBaEiwAeqfvyvejmZr7HIM1T1MNy1dCwP7kOLd_ogCufHIYuAbtRsHzpL8YcUPbcxoCrY8QAvD_BwE

 

In short: depends on the drug you are taking, if you are taking it as prescribed; but as a rule you get maximum protection after 3 weeks of use for the daily pill. 

Thank you.

[SirBillybob]

The answer is in two parts as I assume a “top” wonders about the confluence of drug concentrations in his bloodstream and mucosal tissue, while not typically exposed to semen, unless of course residual infected semen in the “bottom’s” rectum from very recent encounters which is rare .

Two factors: Insertive anal and time to PrEP protection.

The time to protection in terms of drug concentrations in penile mucosal tissue is not as clear as for rectal mucosal tissue but it is reasonable to assume similar or more tentative. The point is that urethral, glans and foreskin tissue is vulnerable to infection from virus contained in rectal mucosal tissue fluids and traces of rectal blood plasma possibly present, but transmission risk is less than for receptive intercourse. However, bacterial STI infection could increase risk as well.

If a “top” trades off some degree of wait time to peak drug concentration levels, the point at which the advantage of lower behavioural transmission risk by virtue of insertive position is lost is unknown. 

Edited November 25 by SirBillybob

[Quincy_7]

2 hours ago, SirBillybob said:

The answer is in two parts as I assume a “top” wonders about the confluence of drug concentrations in his bloodstream and mucosal tissue, while not typically exposed to semen, unless of course residual infected semen in the “bottom’s” rectum from very recent encounters which is rare .

Two factors: Insertive anal and time to PrEP protection.

The time to protection in terms of drug concentrations in penile mucosal tissue is not as clear as for rectal mucosal tissue but it is reasonable to assume similar or more tentative. The point is that urethral, glans and foreskin tissue is vulnerable to infection from virus contained in rectal mucosal tissue fluids and traces of rectal blood plasma possibly present, but transmission risk is less than for receptive intercourse. However, bacterial STI infection could increase risk as well.

If a “top” trades off some degree of wait time to peak drug concentration levels, the point at which the advantage of lower behavioural transmission risk by virtue of insertive position is lost is unknown. 

Could you elaborate on the bolded bit? Sorry but I'm not following.

[SirBillybob]

2 hours ago, Quincy_7 said:

Could you elaborate on the bolded bit? Sorry but I'm not following.

One can approximate the relative risk for bottoms as about 12 times that of tops for one episode of intercourse, outside of PrEP considerations. There is no known relative risk factor for intercourse “too soon” following initial PrEP dosing because that time frame is continuous whereas sexual position is binary. The increase in risk is theoretical.

However, the top engaging in intercourse “too soon” forfeits some of the aforementioned risk difference relative to the bottom who delays intercourse until optimal drug levels are obtained. Since penile mucosal tissue drug concentrations may be similar to vaginal concentrations in that it is known such vaginal concentrations are much less and take longer to accrue compared to rectal mucosal tissue (either gender), practice wisdom would not lean towards tops shortchanging the duration of time in which intercourse postponement is recommended.

Edited November 25 by SirBillybob

[+ Notor]

37 minutes ago, SirBillybob said:

One can approximate the relative risk for bottoms as about 12 times that of tops for one episode of intercourse. There is no known relative risk factor for intercourse “too soon” following initial PrEP dosing because that time frame is continuous whereas sexual position is binary. The increase in risk is theoretical. However, the top engaging in intercourse “too soon” loses some of the aforementioned risk difference relative to the bottom that, say, delays intercourse until optimal drug levels are obtained. 

What does all of this mean if you are using Prep on the 2-1-1 dosing?

[SirBillybob]

1 hour ago, Notor said:

What does all of this mean if you are using Prep on the 2-1-1 dosing?

It’s a good question because obviously a one-week lead-in does not occur. Since there is very little difference in drug concentrations and no difference in estimated protection between an average number of 4 doses vs 7 doses weekly, as well as no difference in breakthrough infection comparing 2-1-1 and daily, it is assumed that the 2-dose on-demand lead-in augmentation of drug concentration is sufficient for equivalent protection. Drug concentrations are in fact specifically organized around the risk event. However, the actual breakthrough infection risk cannot be compared for single events within the two uptake versions because a study can only compare by person-time denominators and number of intercourse risk events is impossible to comparatively tally over time. Similarity in breakthrough infection incidence may be a function of greater protection conferred by daily dosing that is undermined by a greater frequency of risk events.

Therefore, the preference is based on convenience and the frequency and capacity to forecast events, or to be able to access some degree of protection for an impromptu encounter. 

That said, full protection is a misnomer. Protection can only be as good as it gets. 

Edited November 26 by SirBillybob

[ApexNomad]

Speak with your doctor or your a healthcare provider about your specific needs and concerns regarding PrEP. They can provide personalized advice, answer all your questions, and ensure you’re using the medication correctly. While forums can be helpful for shared experiences, they are no substitute for professional medical guidance.

[marylander1940]

2 hours ago, ApexNomad said:

Speak with your doctor or your a healthcare provider about your specific needs and concerns regarding PrEP. They can provide personalized advice, answer all your questions, and ensure you’re using the medication correctly. While forums can be helpful for shared experiences, they are no substitute for professional medical guidance.

[PhileasFogg]

I agree with consulting medical professionals.   My research indicated 7 days was sufficient.   Keeping also in mind that the risk as a top WITH an + partner is 0.11%.   Of course, having been around in the 80's, I will admit that the odds of transmission in the table I've linked seem low.

 

[Luv2play]

On 11/29/2024 at 11:07 AM, PhileasFogg said:

I agree with consulting medical professionals.   My research indicated 7 days was sufficient.   Keeping also in mind that the risk as a top WITH an + partner is 0.11%.   Of course, having been around in the 80's, I will admit that the odds of transmission in the table I've linked seem low.

 

In the risk figure of 0.11percent you cite, does that apply to pos partners who have undetectable status or those who have a detectable viral load?

[PhileasFogg]

39 minutes ago, Luv2play said:

In the risk figure of 0.11percent you cite, does that apply to pos partners who have undetectable status or those who have a detectable viral load?

If I’m reading the table in the link correctly, zero%

[SirBillybob]

19 hours ago, Luv2play said:

In the risk figure of 0.11percent you cite, does that apply to pos partners who have undetectable status or those who have a detectable viral load?

The distinction isn’t made because the synthesized estimate is based on a combination of incidence rates according to estimates of background prevalence, essentially receptive partner HIV positive or serostatus unknown, and of incidence rates based on partner HIV positive, obviously viral load data unavailable overall. 

Since being “top” uncircumcised insertive partner is much higher risk it is odd that the final estimate of .11% did not seem to incorporate that metric. However the authors point out a UIAI risk estimate of .22% in another study, not stratified according to circumcision.

Interestingly, a “top” anally is more likely to be infected from a positive partner than a woman’s likelihood of acquiring infection from vaginal intercourse with a positive male partner. It can be as much about circulating virus in mucosal secretions as virus in semen. 

Edited December 4 by SirBillybob