Background Rilpivirine is a non-nucleoside reverse transcriptase inhibitor approved for use in a highly active antiretroviral therapy combination. A single-tablet formulation of rilpivirine, tenofovir and emtricitabine is commercially available, and the same for efavirenz, tenofovir and emtricitabine. There are many articles comparing their effectiveness but not many about their use in routine practice.

Purpose To evaluate the impact, in terms of effectiveness and safety, of replacing emtricitabine/tenofovir/efavirenz by emtricitabine/tenofovir/rilpivirine in HIV patients.

Material and methods Retrospective observational study in a tertiary hospital. HIV patients were included who had changed from antiretroviral therapy based on emtricitabine/tenofovir/efavirenz combination to emtricitabine/tenofovir/rilpivirine between February and April 2013.

Both demographic and laboratory variables (HIV viral load, count and CD4 percentage and lipid profile) were measured twice: at the moment of change and 24 weeks after it.

Undetectable viral load was defined as two consecutive determinations of viral load lower than 20 HIV copies/mL.

Data were obtained from medical records and from the outpatient dispensing module of ATHOS-APD Pharmacy Service software.

Results Twenty patients (three women) were included. The mean age was 47 (minimum 38, maximum 79) years old. The results of laboratory variables at baseline and 24 weeks of change were: undetectable viral load [18 (90%) patients vs. 19 (95%)]; and percentage of CD4 lymphocytes count [652 cells/uL (35%) vs. 675 (37%)].

Regarding the lipid profile, the mean value of cholesterol (mg/dL) before and after changing was 195 and 175, respectively. The average triglyceride levels (mg/dL) were 126 and 116.

Conclusion Our results suggest that emtricitabine/tenofovir/efavirenz and emtricitabine/tenofovir/rilpivirine can be exchanged without affecting the effectiveness and safety of antiretroviral treatment. This strategy could be useful in the future to provide a treatment based on efficiency criteria.

References and/or Acknowledgements 1Molina JM. Rilpivirine vs. efavirenz in HIV-1 patients with baseline viral load 100,000 copies/ml or less: week 48 phase III analysis

No conflict of interest.