[About the author.]
It was asked online from South Africa I think (with very little initial context) whether a prescription of a daily single tablet regimen (STR) of HIV antiretrovirals (ARVs) Tenofovir disoproxil fumerate (TDF), Lamivudine (3TC), and Dolutegravir (DTG) was A.) PrEP [prevention via Pre-Exposure Prophylaxis among those who are HIV negative] … Or B. ART [treatment via (combination) antiretroviral therapy or (c)ART among those who are living with HIV].
Here’s a response that I never posted:
TL;DR: Your care pro knows best. Most commonly, that combination of ARVs is being used for 1st-line HIV treatment, but it could also be deployed for prevention via PEP (or conceivably even tried as PrEP in desperate or confused times). Either way, several different ARVs are used to treat HIV *AND* for preventing it too, depending on how/when/where/with whom they’re used. We’re lucky these drugs are so versatile, flexible, safe, and powerful that way.
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Just to clarify (and lest we be confused by any inadvertent serophobia imbedded in the question), ARVs *are* the same drugs use for HIV prevention via PrEP, PEP (post-exposure prophylaxis), PMTCT (prevention of mother-to-child transmission), and TasP (treatment-as-prevention) alike as for HIV treatment, depending on which drugs are being taken, who is taking them, why they are taking them, when/how they are taking them, who is prescribing them, and which country’s health authority is providing the guidance/recommendation for taking them.
The three main Tenofovir-based combos currently on the market (TDF/3TC, TDF/FTC, TAF/FTC… and maybe TAF/3TC one day as a 4th if such a generic combo pill is ever manufactured?) serve as BOTH components of treatment regimens for HIV (when combined, like in the example that prompted this explainer, usually with DTG for 1st-line, WHO-recommended HIV therapy or a different, 3rd ARV) and as stand-alone prevention pills for HIV (PrEP, or usually as a backbone when combined also with a 3rd drug for PEP or for TasP).
[NB: Indeed, we’ll soon see HIV ARVs Dapivirine (DPV, the “PrEP DapiviRing” for receptive vaginal sex …And receptive front hole sex too hopefully) and Cabotegravir (CAB, the bi-monthly long acting injectable Cabotegravir, “LAI CAP PrEP,” for all forms of sex) exiting the HIV research pipeline to join this growing list of ARVs that are being put to work in this flexible HIV-fighting manner.]
Here, in one bottle, TDF/FTC/DTG, as pictured above, could most likely be for treatment/TasP or maybe PEP …Or, surprisingly (though highly unlikely) even for PrEP if a care provider made a mistake 🤦🏿♂️ or were under severe local resource constraints 🤷🏿♂️. Again, concluding any of those, though, depends on info that’s not in the original post. 🤭
So, it’s a great strategy to consult your care provider or trusted, local health authorities and resources, which, in this case, include South Africa’s 2019 HIV management guidelines update (echoing a point already made in the conversation).
Hope this helps … Too. 😉
Prophylaxis 