Single-tablet antiretroviral treatment (once daily)
===================================================

* Nisha Andany
* Wayne L. Gold

## Single-tablet antiretroviral treatment taken once daily improves adherence and quality of life compared with multiple-pill regimens

Current guidelines recommend combination antiretroviral treatment for all patients with HIV infection.1,2 The backbone of this treatment regimen is a dual nucleoside reverse transcriptase inhibitor combination, typically tenofovir/emtricitabine or abacavir/lamivudine, which is combined with a non-nucleoside reverse transcriptase inhibitor, integrase strand-transfer inhibitor or boosted protease inhibitor.3 A meta-analysis of randomized controlled trials (RCTs) showed higher pill burden is inversely associated with adherence to combination antiretroviral treatment and virologic suppression, which provides a rationale for using single-tablet regimens.4

## Abacavir/lamivudine/dolutegravir has the highest genetic barrier to resistance; however, there is a risk of hypersensitivity

Abacavir/lamivudine/dolutegravir is recommended as first-line treatment based on RCT evidence.1,2 Abacavir is associated with severe hypersensitivity reactions in patients with the HLA-B5701 allele.1,3 Pretreatment genetic testing is indicated, and abacavir should be avoided if test results are positive for the presence of the allele.2,3 Dolutegravir is an integrase strand-transfer inhibitor with minimal adverse effects and a high genetic barrier to resistance.1–3

## Tenofovir/emtricitabine/efavirenz is associated with neuropsychiatric adverse effects

Tenofovir/emtricitabine forms the backbone in three of four single-tablet regimens and is the preferred treatment for HIV/hepatitis B virus co-infection.1 Tenofovir/emtricitabine/efavirenz is recommended only as an alternative regimen, because efavirenz is associated with neuropsychiatric symptoms and may increase suicidality.1,2 Tenofovir may cause renal toxicity and osteoporosis.1–3

## Tenofovir/emtricitabine/rilpivirine is less effective in patients with pretreatment HIV viral loads greater than 100 000 copies/mL or CD4 counts less than 200 cells/μL

Tenofovir/emtricitabine/rilpivirine should not be prescribed as initial treatment for these patients but is a recommended alternative regimen.1–3 Rilpivirine is a non-nucleoside reverse transcriptase inhibitor with less central nervous system toxicity than efavirenz.1 Adequate absorption requires administration in conjunction with a high-energy meal (> 400 kcal).1 Rilpivirine should not be prescribed to patients taking proton pump inhibitors and should be prescribed with caution in patients taking other acid-lowering drugs.1,3

## Tenofovir/emtricitabine/elvitegravir/cobicistat is well-tolerated but associated with multiple drug interactions

Tenofovir/emtricitabine/elvitegravir/cobicistat is recommended first-line therapy based on RCT evidence.1 It is contraindicated if creatinine clearance is less than 70 mL/min.1,3 Elvitegravir, which is an integrase strand-transfer inhibitor, has a lower genetic barrier to resistance than dolutegravir.1,2 Cobicistat is a cytochrome P450 3A4 inhibitor that acts to increase elvitegravir levels in plasma.2 However, it has the potential for multiple drug interactions (e.g., with statins and rifampin).1–3

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## Footnotes

*   **Competing interests:** None declared.

*   This article has been peer reviewed.

## References

1.  Panel on Antiretroviral Guidelines for Adults and Adolescents. Guidelines for the use of antiretroviral agents in HIV-1 infected adults and adolescents. Bethesda (MD): Department of Health and Human Services; 2014. Available: [www.aidsinfo.nih.gov/contentfiles/adultandadolescentgl.pdf](http://www.aidsinfo.nih.gov/contentfiles/adultandadolescentgl.pdf) (accessed 2015 Oct. 16).
    
    

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4.  Nachega JB, Parienti J, Uthman OA, et al. Lower pill burden and once-daily antiretroviral treatment regimens for HIV infection: a meta-analysis of randomized controlled trials. Clin Infect Dis 2014; 58:1297–307.
    
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