Objectives: To describe the efficacy and tolerability of switching to raltegravir (RAL) in virologically
suppressed HIV-1-infected patients during routine clinical practice.
Methods: A total number of 263 subjects (189 men, median age 48.1 years) with HIV-1 RNA < 50 copies/mL for ≥ 6
months were switched to RAL (400 mg b.i.d). Reasons for change were toxicity (49.0%), drug interactions (6.1%) or
convenience (28.6%) (switch from subcutaneous to oral treatment 22.4%, improvement of posology 3.4%). Patients were
followed up to 24 months after switching to RAL. Primary end-points were tolerability and virological failure defined as
two consecutive measures of HIV-1 RNA > 50 copies/mL.
Results: After a median of 12.4 months (range 2.8-26.4 months), virological failure was observed in 6 (2.3%) patients (2.2
per 100 person-years [95%CI 0.9-4.6]), while AIDS occurred in 1, drug discontinuation in 4, 3 patients died and 10 were
lost to follow-up. The median CD4+ T cell count increased from 460 cells/mm3 to 508.6 cells/mm3 (P < 0.001).
Conclusions: Switching to RAL in clinical practice was mainly driven by toxicity, convenience or interactions, they were
well tolerated and secured virologic suppression in the vast majority of patients.