Does PEP prevent HIV like PrEP does?

[BritishCumdump]

I've been to my 3-monthly PrEP review today and foolishly told the doctor that I had unprotected sex with a stranger on Sunday without taking my event based prep (I'd just run out). I know that this is my fault and risky but I was pretty sure the guy was neg. It wasn't intentional it's just he was fisting me and then decided to jerk off inside me and I just kinda went with it. 

Anyway the doctor insisted that I start on a 28 day course of PEP and wouldn't give me my regular PrEP. 

The thing here is I've literally got a gangbang cumdump session organised for the weekend and I don't want to be without my PrEP for this so I'm wondering whether the stuff I've been given for PEP will protect me from HIV. Also, if I did get unlucky and infected on Sunday, would I be infectious to others this early on (within a week). 

The pills I've been given for PEP are 600mg Raltegravir and 200/245mg Emtricitabin / Tenofovirdisoproxil 

 

Thanks for any help! 

[FHL]

Not a doctor.

My understanding is that PEP is just a strong dose PrEP. Common HIV medicine includes

• TDF/FTC (Tenofovir Disoproxil Fumarate/Emtricitabine, e.g. Truvada)
• TAF/FTC (Tenofovir Alafenamide/Emtricitabine, e.g. Descovy)
• Raltegravir (e.g. Isentress)
• Dolutegravir (e.g. Tivicay)

For PrEP you take either Truvada or Descovy usually. For PEP, you are taking at least two (such as Truvada + Isentress) at higher doses.

If you have been taking PrEP every day and now switch to PEP, I think you should be fine. PrEP, when taking as directed, should prevent the vast majority of HIV infections, and switching to PEP, in theory it should only offer you more protection cos it's more pills. However, if prior to your unprotected sex last Sunday you were not taking PrEP as directed, taking PEP is not a "I can do whatever I want within these 28 days"--it only serves as a last resort for protection for that one time of unprotected sex.

Even if you were infected on Sunday, it would be unlikely for you to be infectious within a week.

[BritishCumdump]

2 minutes ago, FHL said:

Not a doctor.

My understanding is that PEP is just a strong dose PrEP. Common HIV medicine includes

• TDF/FTC (Tenofovir Disoproxil Fumarate/Emtricitabine, e.g. Truvada)
• TAF/FTC (Tenofovir Alafenamide/Emtricitabine, e.g. Descovy)
• Raltegravir (e.g. Isentress)
• Dolutegravir (e.g. Tivicay)

For PrEP you take either Truvada or Descovy usually. For PEP, you are taking at least two (such as Truvada + Isentress) at higher doses.

If you have been taking PrEP every day and now switch to PEP, I think you should be fine. PrEP, when taking as directed, should prevent the vast majority of HIV infections, and switching to PEP, in theory it should only offer you more protection cos it's more pills. However, if prior to your unprotected sex last Sunday you were not taking PrEP as directed, taking PEP is not a "I can do whatever I want within these 28 days"--it only serves as a last resort for protection for that one time of unprotected sex.

Even if you were infected on Sunday, it would be unlikely for you to be infectious within a week.

Thank you for getting back to me. This is really good information. I hadn't taken PrEP the 5 days before getting fucked which is why I was concerned. I guess I'll take the pills given and see what happens. I just didn't realise how ignorant I was about the specifics of PEP/PrEP before being in this situation. 

[hairyone]

You are not being foolish for telling the doctor what happened. He is there to keep you well. You need that four-week PEP and (most likely) it will keep you from getting that deadly disease. 

Don't stop taking the PEP until you go through the entire course. Stopping it early could cause the virus you may have to become resistant to the medication. 

No need to go back to PrEP until you finish the PEP. The PEP would cover you for your gangbang just as well as the PrEP.

(I am not a doctor.) 

[viking8x6]

2 hours ago, BritishCumdump said:

The thing here is I've literally got a gangbang cumdump session organised for the weekend and I don't want to be without my PrEP for this so I'm wondering (1) whether the stuff I've been given for PEP will protect me from HIV.

(2) Also, if I did get unlucky and infected on Sunday, would I be infectious to others this early on (within a week). 

The pills I've been given for PEP are 600mg Raltegravir and 200/245mg Emtricitabin / Tenofovirdisoproxil

(1) Yes. 200/245mg emtricitabine/tenofovir disoproxil is the same as Truvada (though a slightly different dose than standard PrEP), and the raltegravir will only help.

(2) Extremely unlikely, especially after you've started the PEP (which will stop the infection from progressing, and therefore the viral load from increasing).

[JamesL100]

I think Post Exposure (PEP) could be up to 7 days after, more effective the sooner after. I can't recall about Pre Esposure) PrEP.
I never took either but from what I remember in gay mags the pill contained two components that were in a standard (but now historic) ART.
Your clinic doctor should be able to explain more, though 28 days does seem somewhat long. It's interesting to find current regimens.

[BootmanLA]

5 hours ago, JamesL100 said:

I think Post Exposure (PEP) could be up to 7 days after, more effective the sooner after. I can't recall about Pre Esposure) PrEP.
I never took either but from what I remember in gay mags the pill contained two components that were in a standard (but now historic) ART.
Your clinic doctor should be able to explain more, though 28 days does seem somewhat long. It's interesting to find current regimens.

PEP is generally considered effective ONLY if started within 3 days at the max - and the closer to right after potential exposure, the better.

PEP is extended for 28 days because unlike with PrEP (where the sex occurs with a baseline level of antivirals already in your system), PEP is trying to kill off the infection AFTER you've been exposed but hopefully before it takes hold in your system.

With PrEP, taking it for 2 days after (in addition to the larger dose earlier on the day of, or as part of a daily ongoing dose) is enough because the virus hit the antivirals in your system immediately. But with PEP, the virus has already had some number of hours or days to start its work, so a much longer treatment to prevent it taking hold is required.