Viral suppression with antiretroviral therapy after single drug substitution of efavirenz with dolutegravir at an HIV Centre in Karachi, Pakistan

Background: AIDS was first reported in the 1980s. The HIV prevalence rate among Pakistani adults is 0.2%. The Sindh Center for AIDS Control Programs (SACP) was established in Karachi in 2006. In 2018, the SACP introduced the integrase chain transfer inhibitor dolutegravir (DTG) and lamivudine (3TC) and tenofovir diproxilfumarate (TDF). Patients who developed virological failure on Efavirenz, 3TC, and TDF were switched to DTG/3TC/TDF. As the two nucleoside reverse transcriptase inhibitors remained the same, EFV and DTG were effectively substituted as single agents. We assessed immunological, virological and clinical responses to DTG. Material and Methods: A retrospective chart review was conducted at the SACP of adults with virological failure on EFV/3TC/TDF who were switched to DTG/3TC/TDF from April 2019 till November 2023. Results: The 14 patients were switched after a mean of 28.2 months of prior antiretroviral therapy with mean CD4 of 116 cells/mm3. Mean age was 28.4 years with 7 (50.0%) males.12 were adherent to the DTG regimen; 11 (92 %) achieved viral suppression. The Mean period of suppression was31 months. There was no clinical or immunological failure with upsurge of mean CD4 to 632 cells/mm3. Conclusion: The patients with virological failure on an efavirenz-based regimen are likely to have viral suppression after switch to a dolutegravir-based routine even if they potentially have NRTI resistance. These results are relevant to HIV programs in resource-poor settings where switches between regimens are often implemented without frequent viral load or resistance testing. Keywords: HIV, Dolutegravir, Efavirenz, Tenofovir, Viral suppression, CD4 count