Single-tablet regimens (STRs) may facilitate improved clinical outcomes compared with once-daily multiple-tablet regimens (MTRs), according to a study published in AIDS Care.
In the mid-1990s, marked reduction in HIV infection mortality was due to highly active antiretroviral therapy (HAART). However, benefitting from this regimen required high-level adherence involving dozens of pills each day. Today, newer regimens are only taken once daily, and some require a single daily tablet. Currently, STRs are standard with many providers because it is believed that the decreased pill burden improves the likelihood of virologic suppression, medication adherence, tolerability, and the patient’s overall quality of life. Compared with less-preferred MTRs, higher adherence to STRs is seen, but limited evidence is available on the impact of once-daily STR virologic outcomes compared with once-daily MTR.
In this retrospective study, adherence to ART, retention in care, and virologic outcomes in patients receiving once-daily STRs and MTRs were evaluated at Thomas Street Health Center in Texas. This study included 1028 patients who filled prescriptions in-house and were initiating 1 of 5 standard first-line tenofovir-based once-daily regimens between January 2008 and December 2011.
All patients receiving STR (n=622) were prescribed coformulated tenofovir disoproxil fumarate (TDF)/emtricitabine (FTC)/efavirenz. Of all the MRT subjects (n=406), 65.2% were prescribed TDF/FTC/atazanavir/ritonavir and 34.8% were prescribed TDF/FTC/darunavir/ritonavir.
When compared with once-daily MTRs, STRs were found to be associated with higher rates of retention in care and virologic suppression in the first year. This association continued even after adjustment for observed confounders like choice of initial ART regimen. Retention of care 1 year after ART initiation was achieved in 80.7% of patients receiving STR and 72.7% of patients receiving MTR (adjusted odds ratio [aOR] 1.49; P =.011). Regardless of regimen change, virologic suppression at any point within 1 year occurred in 84.4% of patients receiving STR and 77.6% of patients receiving MTR (aOR 1.41; P =.04).
No significant difference in adherence was seen between STR and MTR. Pharmacy fill data were used as an imperfect measure of adherence and assessed by calculating the percentage of days covered (PDC); ³80% for the year was considered adherent. Of the study participants, 33.0% of those receiving STR and 30.1% of those receiving MTR achieved at least 80% PDC (aOR 1.04; P =.77).
As this study stands out as one of the few published studies directly comparing once-daily STR and MTR regimens in a clinical setting, the study investigators concluded that “patients taking STRs demonstrate similar adherence and better retention in HIV care and better virologic suppression than do patients on MTRs.”
Hemmige V, Flash CA, Carter J, Giordano TP, Zerai T. Single tablet HIV regimens facilitate virologic suppression and retention in care among treatment naïve patients [published online February 13, 2018]. AIDS Care. doi:10.1080/09540121.2018.1442554