How long is PrEP (Truvada) detectable in blood?

[tonio]

Hello,

I take on-demand PrEP (Truvada) through a specific GP (specialised in STDs) and the last pill I took was on Saturday, November 9. 

Now, I have to do a blood test for a completely unrelated reason (I have to test for glucose and kidneys) through my regular GP. The blood test is scheduled tomorrow, on November 30.

 

How long is Truvada detectable in the blood after last intake? My regular GP doesn't know anything about the fact I take Truvada, and I wouldn't like to disclose to him that information.

 

Is Truvada gonna be detectable in my blood 3 weeks after the last pill?

 

Edited November 29 by tonio

[NicNorth]

I’m not an expert but I rather think that (partially due to costs) the tests you describe only detect the things they are designed to test for. My GP tests me for both of the things you list but has no knowledge of my taking PREP.  I’ve seen the resulting report which only appears to relate to the aspects of kidney function and blood sugar.  
 

To satisfy your self fully it’s worth contacting the PREP prescriber. 

[tonio]

11 minutes ago, NicNorth said:

I’m not an expert but I rather think that (partially due to costs) the tests you describe only detect the things they are designed to test for. My GP tests me for both of the things you list but has no knowledge of my taking PREP.  I’ve seen the resulting report which only appears to relate to the aspects of kidney function and blood sugar.  
 

To satisfy your self fully it’s worth contacting the PREP prescriber. 

Yeah, but my question is: how likely is it that the blood test is gonna detect something weird that could be related to me taking PrEP?

[Lt97]

Blood tests won't show PrEP in them since there's no test out there that looks for everything - they're all specific for certain proteins, and no test exists to look just for HIV antivirals as far as I know. At most, there may be some changes to liver tests in some cases, but nothing your GP would see and instantly think "Oh he's on a drug/medication".

[viking8x6]

30 minutes ago, tonio said:

Yeah, but my question is: how likely is it that the blood test is gonna detect something weird that could be related to me taking PrEP?

If you haven't been getting your kidney function checked regularly as part of the PrEP, then the blood test might detect an issue with kidney function caused by the PrEP. But that's the whole idea, innit? You really do want to keep your kidneys working, and if Truvada is messing with them, your PrEP provider needs to know that and switch drugs.

[NicNorth]

My PREP provider always checks kidney function at the same time as checking for HIV.  Standard procedure in the UK.  People with lower kidney function msy be offered Discovy which has been found to be more gentle on kidney function.

[hairyone]

Why do you hide your medical practices and situation with your doctors? They work for you and can't do their jobs correctly without having all your info. If you can't trust them or confide in them, fire them and find one that will work with you. You deserve complete care.

[Tiboer]

I’ve met a number of closeted, married guys who use on-demand PrEP (2-1-1).  They get their PrEP through an online doc.  
 

Tonio, be sure to take 400 mg of Doxycycline too to prevent STIs

[Erik62]

11 hours ago, viking8x6 said:

If you haven't been getting your kidney function checked regularly as part of the PrEP, then the blood test might detect an issue with kidney function caused by the PrEP. But that's the whole idea, innit? You really do want to keep your kidneys working, and if Truvada is messing with them, your PrEP provider needs to know that and switch drugs.

Apart from returning a Positive test which, (should never be unexpected, even with PReP, condoms or both), anything unexpected is the reason for testing. UNEXPECTED is rarely good news & the sooner tests that show ANY problems, allow it to be treated that is to YOUR BENEFIT. 

[BootmanLA]

On 11/29/2024 at 8:57 AM, tonio said:

Yeah, but my question is: how likely is it that the blood test is gonna detect something weird that could be related to me taking PrEP?

How often do you take an on-demand dose set of PrEP? You say the last pill you took was Nov. 9. Do you (on average) take that 2-1-1 series once a week, once a month, every couple of months?

That, more than anything else, will determine if it's affecting your body in a way that routine lab work will detect. In other words, a 2-1-1 series of PrEP, once a month, is highly unlikely to cause, say, enough damage that it would be detectable on standard screening tests. If you were taking a series like that once a week, on the other hand, that's more than half of what someone taking it daily would be getting, so it's not impossible that (a) it MIGHT be affecting your liver or kidneys or whatever AND (b) that damage was beginning to show via lab work.

But the majority of people on PrEP, even taking it daily, don't have that kind of damage. So chances are pretty good that nothing will appear amiss.

That said: you don't say why you don't want your regular GP to know you're on PrEP. But if he doesn't, he may end up prescribing something else for you (for some unrelated illness or condition) that, in turn, interacts with your PrEP in a negative way, rendering it less effective. It's NEVER a good idea to hide medications prescribed by one doctor from another, particularly if the latter doctor is one you see regularly.

[tonio]

On 12/1/2024 at 2:02 AM, BootmanLA said:

How often do you take an on-demand dose set of PrEP? You say the last pill you took was Nov. 9. Do you (on average) take that 2-1-1 series once a week, once a month, every couple of months?

That, more than anything else, will determine if it's affecting your body in a way that routine lab work will detect. In other words, a 2-1-1 series of PrEP, once a month, is highly unlikely to cause, say, enough damage that it would be detectable on standard screening tests. If you were taking a series like that once a week, on the other hand, that's more than half of what someone taking it daily would be getting, so it's not impossible that (a) it MIGHT be affecting your liver or kidneys or whatever AND (b) that damage was beginning to show via lab work.

But the majority of people on PrEP, even taking it daily, don't have that kind of damage. So chances are pretty good that nothing will appear amiss.

That said: you don't say why you don't want your regular GP to know you're on PrEP. But if he doesn't, he may end up prescribing something else for you (for some unrelated illness or condition) that, in turn, interacts with your PrEP in a negative way, rendering it less effective. It's NEVER a good idea to hide medications prescribed by one doctor from another, particularly if the latter doctor is one you see regularly.

Basically I use on-demand PrEP about twice or three times a year. I don't use that many tablets (maybe 30 tablets a year tops).

Just received the bloodtest results, and kidney filtration function appears to be excellent. Nothing else to emphasize in the rest of the blood test.

So in my case, on-demand PrEP doesn't seem to affect kidneys.

Edited December 2 by tonio

[BootmanLA]

On 12/2/2024 at 8:28 AM, tonio said:

Basically I use on-demand PrEP about twice or three times a year. I don't use that many tablets (maybe 30 tablets a year tops).

Just received the bloodtest results, and kidney filtration function appears to be excellent. Nothing else to emphasize in the rest of the blood test.

So in my case, on-demand PrEP doesn't seem to affect kidneys.

It shouldn't, not for anyone who's using it 2-3 times a year.

Though I'll note: the recommended dosage calls for 4 tablets (2 before sex, 1 a day later, 1 a day after that) per sexual encounter. If you're only doing that 2-3 times a year, that should be between 8 and 12, not 30 tablets. 

There's no harm in taking it for an additional day or two after sex beyond the 2 recommended, of course. Either way, a few isolated occurrences like this should cause no decline in kidney or liver functions - unless the person was already experiencing a failing kidney or liver.

[tonio]

On 11/30/2024 at 3:11 AM, Tiboer said:

I’ve met a number of closeted, married guys who use on-demand PrEP (2-1-1).  They get their PrEP through an online doc.  
 

Tonio, be sure to take 400 mg of Doxycycline too to prevent STIs

The recommended dosing for DoxyPEP is 200mg within 2 to 3 days

Edited December 5 by tonio

[DPG2349]

On 11/29/2024 at 7:11 PM, Tiboer said:

I’ve met a number of closeted, married guys who use on-demand PrEP (2-1-1).  They get their PrEP through an online doc.  
 

Tonio, be sure to take 400 mg of Doxycycline too to prevent STIs

Yup.