Therapeutic Monitoring of Antiretroviral Drugs in Immunologically Stable HIV Patients on ART Treatment

In HIV, highly active anti-retroviral therapy helps patients to regain the immune CD4+ cell count. Among all antiretroviral therapy (ART) regimens tenofovir based regimen (TLE; Tenofovir (TDF) + Lamivudine (3TC) + Efavirenz (EFV)) has become the most preferred first line regimen. Present study aimed to identify the therapeutic levels of drugs in tenofovir based regimen in immunologically stable HIV patients. A total of 35 dried blood samples were obtained from HIV patients on TLE treatment visiting ART centre, Mahatma Gandhi Memorial (MGM) Hospital, Warangal, Telangana, during September 2017 to March 2018. Patients with good adherence, without history of smoking & alcoholism and with CD4+ cell count > 350 cells/mm3 were included. Estimation of drugs was done using pre validated liquid chromatographic method. In total of 35 patients, females were accounted for 62.86%. Patients of this study showed high percentage of illiterates (48.57%) and daily labors (34.29%). As EFV is a narrow therapeutic index drug it showed significant difference in its plasma therapeutic levels (0.005**) whereas TDF & 3TC were not. Total of 8.57% and 91.43% patients were showed EFV plasma levels below and above therapeutic levels respectively. Though the study patients observed with good immunological status, high percentage of patients identified with toxic levels of EFV concentrations. But none of the patients showed any symptoms of toxicity, they are at risk to develop clinical toxicity in future. Present study results suggesting dose adjustments and monitoring of drug levels in these patients to avoid early treatment failures and toxicity. Keywords: HIV, CD4+ cell count, Tenofovir regimen, Therapeutic level, Monitoring