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Is this Resistance?

  • 1.  Is this Resistance?

    Posted 06-04-2021 19:35
    I have a patient diagnosed and put on Bic 9 months ago.  He takes his meds daily.  His VL went from UD to 85 recently.  I ordered resistance and genotype for Integrase etc.
    Am I overreacting?  If it is resistance, can I handle the analysis and response from my Primary Care clinic, or will I have to seek a higher level of 
    care?  The patient has no other medical conditions or medications.  Is there a blood level testing for Bic?  Is VL 85 after 9 months of treatment a sure sign of resistance?  He has been UD until a few months ago.  He has not been ill or had any complications from ARV.

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    Samuel Samalin
    Los Angeles CA
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  • 2.  RE: Is this Resistance?

    Posted 06-05-2021 15:16

    Likely overreacting - do check adherence and possible interactions (cations on an empty stomach with meds?) but levels below 200 are generally not something to worry much about.



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    Susan LeLacheur
    Whitman-Walker Clinic
    Washington DC
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  • 3.  RE: Is this Resistance?

    Posted 06-05-2021 15:21
    I have a patient diagnosed and put on Bic 9 months ago.  He takes his meds daily.  His VL went from UD to 85 recently.  I ordered resistance and genotype for Integrase etc.
    Am I overreacting? Good idea to check for mutations or resistance, typical resistance is M184 V/I, which confers resistance to 3TC/FTC.
    If it is resistance, can I handle the analysis and response from my Primary Care clinic, or will I have to seek a higher level of 

    care? Higher level of care. Resistance to first line Bic or DTG is rare and the goal is resuppression. 
    The patient has no other medical conditions or medications. 
    Is there a blood level testing for Bic? Not that I am aware of or familiar with. Resistance testing should be next logical step. 
    Is VL 85 after 9 months of treatment a sure sign of resistance? Not resistance, just a brief spike. Viral load is not over 200 so not likely virological failure.  I would inquire first about adherence to meds, and then if the trend shows a further increase in viral load over 200, then I would inquire about any new sex partners, IV drug use or other potential avenues of resistance. 

    He has been UD until a few months ago.  He has not been ill or had any complications from ARV.


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    Henry Delu
    Los Angeles CA
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  • 4.  RE: Is this Resistance?

    Posted 06-05-2021 15:50

    Hi Samuel- 
    a viral load of 85 copies is, in my opinion, nothing to worry about. The threshold to start thinking is over 200 copies. And realistically you won't be able to amplify any resistance on a genosure at 85 copies as it needs 400 copies. Remember resistance is a breakthrough occurrence due to suboptimal drug levels on virus, thus the dominant virus has the mutated species. At 85 copies it's hard to really quantify since this can also be what is called a "blip" which are viral loads under 200 copies and then go back to undetectable. 


    if you ran a genosure archive I would be really cautious with how you interpret that test as it is specifically for people who are NOT failing to see in the pro viral DNA what mitigations there are in general, not just in that moment of failure.

    first thing I would do is make sure they are not taking any cations like mag or iron, like Maalox or tums. There actually is a small drug interaction and it should be kept in the forefront to remind patients of this (package insert has all the time requirements or food requirements) . Second, I would do counseling on adherence, which I think many people have gotten away from because they see the undetectable VL and think that is enough, but counseling on adherence, dosing etc is really good to do. 3rd just recheck the viral load. No need to jump to an expensive test when it's not warranted. 


    Angela 



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    Angela Kapalko
    Physician Assistant Chairperson for AAHIVM
    Philadelphia FIGHT CommunityHealth Centers
    Philadelphia PA
    akapalko@fight.org
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  • 5.  RE: Is this Resistance?

    Posted 06-05-2021 16:26
    From a pharmacist viewpoint: Double check with the patient that he's not taking any calcium antacids, iron supplements, multivitamins or herbals which could effect absorption/bioavailability of bictegravir. Some patients don't consider these "medications" so they don't report.

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    Amy Moss PharmD, AAHIVP
    Houston TX
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  • 6.  RE: Is this Resistance?

    Posted 06-05-2021 16:44
    Hi - this happens often in my hospital base clinic - I do think it could lab variability - in these circumstances - I do repeat the VL 1 month later and usually it comes back UD.  I would not assume that the pt is failing the ARV.

    My 2 cents.  Hope it is helpful.

    Sara Back FNP
    Bronx NY

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    Sara Back
    North Central Bronx Hospital
    New York NY
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