Background Long term adverse effects, expense and difficulty of adherence to antiretroviral therapy (ART) have led to the study of simpler maintenance therapies. Switching from triple therapy to dual therapy seems to be effective and safe, but few data exist in clinical practice.

Purpose To assess the effectiveness and safety of simplification to a dual therapy in experienced HIV patients.

Material and methods A retrospective study including experienced HIV patients switching from triple to dual therapy between August 2009 and January 2015.

Demographic and clinical characteristics, viral load (VL), CD4⁺ T cell count, CD4/CD8 ratio, fasting lipid profile, and liver and renal function were recorded when dual therapy was started and at week 24. Previous ARTs, reason for change to dual therapy and adverse events leading to discontinuation of the new regimen were also evaluated.

Results 67 patients were included, 58.2% were male with a median (IQR) age of 50 (47 to 54) years. Reasons for switching to dual therapy were: presence of adverse events (44.8%), treatment simplification (26.9%), virological failure (14.9%), immunological failure (3%) and other (25.4%). The most frequent drug combinations were: a ritonavir boosted protease inhibitor with maraviroc (43.3%), a ritonavir boosted protease inhibitor with lamivudine (40.3%) and rilpivirine and dolutegravir (5.97%). Effectiveness and safety results are shown in table 1.

All values are expressed as median (IQR), unless otherwise indicated.

18 patients (26.9%) interrupted the dual therapy: 4 patients (6.0%) switched to a triple therapy and 14 (21.0%) to a different dual therapy due to drug interactions (27.8%), metabolic disorders (22.2%), simplification (16.7%), gastrointestinal intolerance (11.1%) and failure to achieve an undetectable VL (5.6%).

Conclusion Switching to dual therapy for maintenance treatment is effective, safe and not inferior to triple therapy in treatment experienced HIV patients.

No conflict of interest.