|Can PEP lead to a false negative on a PCR?
Nov 20, 2009
About three weeks ago I had unprotected anal sex with a man who turned out to be HIV positive. I was the top. I was exposed only to his precum, his saliva and anal mucus. I was not exposed to his semen nor to his blood. Within 24 hours after the encounter I started Combivir. I took only two weeks' worth and then stopped, because I had developed life-threatening side-effects such as shortness of breath, a slow heart rate, palpitations, numbness, dizziness, blurred vision, muscle aches, pins and needles and a burning sensation on my palms and feet. Five days after stopping Combivir I had both an ELISA and a Qualitative PCR come back negative. My physician also examined me and found no swollen glands. I do, however, now have slightly tender, swollen glands below my ears just behind my jaws, and a very dull aching in my groin -- something which is foreign to me. I trust my physician, but he is not an HIV specialist. I am worried that, by taking Combivir for two weeks, I might have inadvertently extended my PCR window period, and might have actually caused a possible HIV infection to become suppressed enough to be undetectable through a blood test, but not enough to avoid seroconversion.
| Response from Dr. Frascino
You had unprotected anal sex with a man who turned out to be HIV positive???? You ignored Dr. Bob's number 1 and number 2 rules!!! My number one rule is that we need to consider that all our sex partners could be HIV infected and therefore take all the necessary precautions to prevent transmission of the virus. My number two rule is always to remember rule number one!
As I have frequently stated in this forum, I recommend anyone who has had an HIV exposure significant enough to warrant a course of PEP be followed by an HIV specialist physician during the 28-day course. Situations such as yours are an excellent example why I make this recommendation. An HIV specialist would have been able to evaluate and manage your "side effects." If necessary, he could have switched you to an alternative PEP regimen so that you could have completed your full 28-day course.
As for post-PEP HIV testing, the published guidelines recommend HIV-antibody tests at six weeks, three months and six months.
HIV PCR RNA tests (viral load) are generally not used for routine HIV diagnosis. You are correct: HIV PCR RNA tests should definitely not be used for diagnostic purposes in someone on PEP. PEP consists of potent antiretroviral drugs, the same drugs we use to treat active HIV infection. If someone is HIV infected and on PEP, the drugs could be suppressing the HIV viral load (PCR RNA) to undetectable levels. This could lead to the wrong conclusion that the person on PEP is not HIV infected when in reality the result is a false-negative. The person could be HIV infected, but the antiretrovirals are suppressing the viral load to undetectable levels.
My advice to you is to follow the routine post-PEP HIV testing guidelines, even though you did not finish your full course of PEP.
You can read much more about PEP in the archives of this forum. I'll reprint a small sample below of what you can find in the archives.
Can PEP meds mimic ARS? (PEP AND THE NEED FOR HIV SPECIALIST, 2009) Aug 22, 2009
Hi Dr. Bob,
Thank you for all you have done and continue to do for people who find themselves scared and bewildered. A twist of humor is also helpful.
I have searched the archives. Simple question, I think, can PEP meds side effects mimic ARS?
Thank you kindly for your answer and please find a donation forthcoming to the foundation.
Response from Dr. Frascino
Simple question, yes. However, the answer is not quite so simple! HIV acute retroviral syndrome (ARS) symptoms are quite variable from case to case. These symptoms are also "non-specific," which means they can be caused by many different conditions (for instance many underlying conditions can cause fever, rash, malaise, etc.). Post-exposure prophylaxis (PEP) is any combination of antiretroviral drugs used to try to abort an HIV infection following an exposure. Each of these drugs has a wide array of potential side effects. Not everyone uses the same PEP regimen and not every drug has the same side effect profile. So since ARS symptoms are broad, varied and non-specific and since PEP regimens are varied with each component drug having a wide array of potential side effects, it is possible (although not highly likely) that some PEP-related side effects could mimic some HIV ARS symptoms. This is one of the reasons I always recommend (when possible) that folks who have had an HIV exposure significant enough to warrant a course of PEP be followed by an HIV specialist during the 28-day course of treatment. An HIV specialist is best suited to evaluate and manage any symptoms that might arise during a course of PEP. (See below.)
Amas, as you can see, not all simple questions have simple answers.
EMS Exposure (PEP AND THE NEED FOR HIV SPECIALIST) Mar 2, 2009
A patient of mine had projectile vomiting and some of it landed in my mouth and eyes. There was no way I could have avoided this. I do not think there is a risk of HIV transmission, however, the hospital put me on Viread and Combivir as a precaution. The patient was homeless, intoxicated, and not forthcoming of his medical history.
What do you think of this situation?
Response from Dr. Frascino
Vomitus (like saliva, urine, tears, sweat, nasal mucous and feces) is not considered to be a risk for HIV transmission unless there is visible blood present. PEP was most likely not warranted. As with all people who have had a potential exposure significant enough to begin a PEP regimen, I recommend you be evaluated and followed by an HIV specialist physician. (See below.) He will take a detailed history and advise whether or not PEP should be continued or modified. Also, since you know the potential source patient, he could be contacted and asked to undergo HIV screening.
pep and the worst year of my life. (PEP AND THE NEED FOR HIV SPECIALIST) Jul 13, 2008
I'm a bit nervous because I just took PEP and I don't know what the side effects are so maybe you can help out with it.
I've been having pains in my right abdomen for about a month now but my liver enzymes are normal. I'm still a bit scared because it is where my liver is.
Yesterday, I has receptive anal sex with a stranger. I put a condom on him and he was doing what he was doing. Then he said, I THINK SOME ONES COMING, So I look around, there was nobody there and looked behind me. Saw that the condom with lube was on the floor and his zipper was zipped up. Didn't think anything of it. Went home and pooped. I saw a glob of his semen in the toilet and was going to kill myself.
My possible exposure before this one was 4 months ago. It was anal receptive without condom with a guy I barely knew who I can't get in touch with. I came down with flu symptoms and was told to test at 3 months and then 6 months and then a year because I got really sick.
So my result was negative today before I started pep. I wanted to know if my testing window period will change for the sexual encounter that took place 4 months ago or should I trust in a 4 month negative??????
PEP treatment is 1 month.
When should I test again.
Should I stop taking the pep?
Does pep have hiv in it that will effect me if I have previously been exposed(4 months ago), ruining my chances of being negative?
I've had the worst luck any guy can have. I didn't have sex for 4 months and the one day I decided to cruise, I got violated.
Will pep have a bad effect on me if I am infected and don't know it from the 4 month issue?
I know that you're the only one that can answer these questions for me.
Response from Dr. Frascino
Why would you think I am the only one who could answer your questions! Your questions are not uncommon or particularly challenging. Any HIV specialist should be able to help. I'm a bit concerned by your first statement, ". . . I just took PEP and I don't know what the side effects are . . . ." The prescribing physician (hopefully an HIV specialist) should have explained potential side effects at the time the medications were recommended. I can't specifically answer this question, because side effects are different from person to person and also the range of potential side effects differs depending on which antiretroviral medications are in the PEP regimen. I'm also concerned about several of your other questions, such as "Does PED have HIV in it?" Questions like this demonstrate a profound lack of understanding of post-exposure prophylaxis and antiretroviral therapy. (The brief response is no, of course these medications do not contain HIV!)
Your multiple concerns clearly demonstrate why I strongly recommend that all folks who have had an HIV exposure significant enough to warrant PEP have an HIV specialist involved in their care. The HIV specialist will:
1. Evaluate and document the HIV risk exposure.
2. Recommend PEP if warranted.
3. If PEP has already been started, the HIV specialist will revise, optimize or suggest discontinuation of the PEP regimen as indicated.
4. Evaluate and manage all PEP-related side effects and toxicities.
5. Evaluate all symptoms, including potential acute retroviral syndrome symptoms, occurring during the course of PEP therapy.
6. Arrange for and interpret post-PEP HIV testing.
My advice to you is to contact an HIV specialist. He or she will specifically address all your concerns in detail. I would also suggest that you be a bit more discerning regarding your sexual partners. When that last jerk said "I THINK SOME ONES COMING," apparently he was talking about himself! If he managed to ditch the condom without your realizing it, you really need to pay more attention to "what he is doing while he's doing what he's doing," particularly when he's "doing" you!
ARS or PEP side-effect? Jul 3, 2008
Thank God for you and this website! Quite concerned over the following:
I'm on PEP (Kaletra and Truvada) after a potential exposure (4 days ago) and noticed yesterday for a time (and again today) that my face is quite warm and I feel flushed. I have had the usual loose stool, stomach-related side-effects of the meds but I'm REALLY hoping that you can tell me if a slight temperature might also be a side effect and not a result of the "ARS" I see so many here concerned about. Obviously self-diagnosis is a BIG mistake, as is worrying and stressing but I'd very much appreciate your honest opinion.
Response from Dr. Frascino
Your question graphically demonstrates the reason I suggest anyone who has had an HIV exposure significant enough to warrant a course of PEP be followed by an HIV specialist. The HIV specialist can document your true degree of HIV risk, optimize PEP regimens, evaluate and manage all PEP-related side effects or toxicities, monitor for and evaluate any possible ARS symptoms and arrange for an interpret all post-PEP HIV tests. Having to take a course of PEP is indeed stressful. Having an HIV specialist involved can significantly reduce that stress. I cannot evaluate symptoms or make diagnoses over the Internet. What I can tell you is that "feeling flushed" and actually having a significant fever are two very different things. Also, even if you were to have an elevated temperature, there are many conditions other than HIV that could be the cause. I can also advise you that symptoms four days after exposure would not be related to HIV. It takes weeks, not days, for the symptoms of acute retroviral syndrome (ARS) to appear.
condom broke during the act Jan 20, 2007
First, Thank you so much for this forum.
about 4 days ago i had vaginal sex with a woman who i later discovered to be very high risk. the condom broke during our act and it was less than 3 or four minutes later that i finished. i don't know if she was hiv positive and have no way of finding out. the following day I went to the emergency room and was perscribed ATRIPLA. and of course i am not feeling very well at all on it. I go to the bathroom often and have the symptoms of a low fever at times during the day. cottonmouth, sore throat ...
I live in san francisco, and am wondering if I should have a follow up visit with a specialist in the area. And How I would find such a doctor.
Also was my risk and exposure high enough to warrant such a drastic step as ATRIPLA?
And of course I am completely freaking out that one stupid drunk moment has damaged my body to such a degree, has anyone built a time machine yet?
Response from Dr. Frascino
Personally, I feel anyone who has had an HIV exposure significant enough to warrant a course of PEP should be followed by an HIV specialist, if possible. The HIV specialist would:
1. Evaluate the risk to see if PEP was really warranted.
2. Optimize the PEP regimen.
3. Evaluate and manage PEP-related side effects and toxicities.
4. Arrange for and evaluate post-PEP HIV testing.
Living in San Francisco, you have many options from which to choose regarding HIV specialist. Certified HIV/AIDS specialist physicians in your area can be located by consulting the American Academy of HIV Medicine Web site, www.aahivm.org.
Finally, if you do find that time machine, let me know. I know millions of folks who want to go back to 2000 and 2004 and recast their presidential vote.
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