The Brazilian Ministry of Health adopted dolutegravir (DTG) as first-line therapy for HIV and recommended switching antiretroviral regimens (ARVs) to DTG-based combinations in stable, virologically suppressed people living with HIV (PLHIV) to improve adherence, tolerability, and reduce adverse effects. This study evaluated the long-term virological impact and tolerability of switching to DTG-based regimens over 240 weeks of follow-up in Salvador, Bahia.

This was a longitudinal retrospective cohort study involving PLHIV who switched to DTG-containing regimens in 2018, followed until 2023 at a state reference center in Bahia. Inclusion criteria: age ≥ 18 years, undetectable viral load before switch, and post-switch viral load data available. Variables analyzed included viral load (real-time PCR, undetectable < 40 copies/mL; virological failure > 200 copies/mL), treatment adherence (percentage of dispensations in 12 months), and sociodemographic and clinical data from records. Analyses were conducted in R Studio (2020). This research is part of the ECOAH cohort, approved by the SESAB Ethics Committee.

A total of 240 PLHIV were included; mean age 47.1 years, 68.3% male, 85.4% from Salvador. Mean duration since HIV diagnosis was 10.5 (± 5.3) years; mean ARV use before switch was 9.0 (± 4.9) years. In 2018, 100% had undetectable viral load, decreasing to 95.4% in 2023. Low ARV adherence increased from 11.7% (2018) to 15.4% (2023). Virological failure episodes were observed throughout follow-up (5.8%), associated with non-adherence but without evidence of resistance. Virological failure rates (VL > 200 copies/mL) were: 1.7% at week 48, 1.3% at week 96, 2.9% at weeks 144 and 192, and 4.6% at week 240. Five (2.1%) cases required switching from DTG due to adverse reactions, and eight (3.3%) discontinued treatment.

Switching to dolutegravir demonstrated high virological efficacy over 240 weeks; however, a decline in adherence levels and challenges in maintaining viral suppression were observed. These results highlight the importance of continuous monitoring and individualized strategies to ensure treatment safety and efficacy among people living with HIV.