[Analysis of the duration of and reasons for changing the first combination of antiretroviral therapy]

Virologic Failure, Clinical Characteristics, and Common Viral Mutations in HIV Patients From Southwestern Colombia: A Nested Case-Control Study

Introduction Virologic failure due to antiretroviral drug resistance is a threat to efforts to control the human immunodeficiency virus (HIV) epidemic. Understanding the factors that influence the genetic and clinical expression of drug resistance is fundamental for infection control. Methods A nested case-control study was conducted on a cohort of adult HIV patients between 2016 and 2022. The cases were defined as patients with a confirmed diagnosis of virologic failure due to drug resistance, as indicated by a viral genotype result. The control group consisted of patients who had not experienced virologic failure or undergone any documented changes to their antiretroviral treatment. The incidence of virologic failure over a defined period was calculated. The characteristics of each group were documented in frequency tables and measures of central tendency. To identify risk factors, multiple logistic regression models were employed, and post hoc tests were conducted. All calculations were performed with 95% confidence intervals, and p-values less than 0.05 were considered significant. Results The incidence of virologic failure over the seven-year study period was 9.2% (95% CI: 7.5-11.2%). Low CD4 T-lymphocyte count (≤200 cells/mm³) at diagnosis (adjOR 14.2, 95% CI: 3.1-64.5), history of opportunistic infections (adjOR 3.5, 95% CI: 1.9-6.4), and late enrollment into an HIV program after diagnosis (>1 year) (adjOR 9.2, 95% CI: 3.8-22.2) were identified as independent predictors of virologic failure. The drugs with the highest rates of resistance were nevirapine (84.6%), efavirenz (82.4%), emtricitabine (81.3%), lamivudine (81.3%), and atazanavir (6.6%). The most prevalent major mutations identified were K103N, M184V, and M46I/M. Approximately 50% of the secondary mutations were identified in protease regions. Conclusions The incidence of virologic failure was low in the study population. The identified risk characteristics allow for the prediction of the profile of patients susceptible to failure and for the early optimization of treatment regimens.

Durability of the first antiretroviral treatment regimen and reasons for change in patients with HIV infection

BACKGROUND

To study the durability of the drugs and coformulations currently used in the first treatment regimen of antiretroviral therapy (ART) for HIV patients, and to examine the reasons for changing this medication.

METHODS

A retrospective observational multicenter study of patients with HIV infection who started a first-line ART regimen between January 2007 and June 2010. The primary outcome variable was the durability of this first ART regimen until discontinued or amended and the reasons for the change. Survival analysis of durability was performed using Kaplan-Meyer curves analysis, and a Cox multiple regression model was constructed to identify associated factors.

RESULTS

A first-line ART regimen was initiated for 600 patients; after 1 year, it had been changed in 172 (28%) cases, with a median duration of 31 months. The main reason for change was toxicity (20.5% of all patients), followed by loss to follow-up (8.3%) and virological failure (5.3%). The most common type of toxicity was gastrointestinal (30%), followed by cutaneous (23%) and neuropsychiatric (18%). The use of non-nucleoside reverse transcriptase inhibitors (NNRTIs) was associated with greater durability than that of protease inhibitors (43 months vs 21 months; P = .001).

CONCLUSIONS

The durability of the first-line ART regimen, based on current antiretroviral drugs and coformulations, is about 2.5 years, with toxicity being the main reason for its modification. Gastrointestinal toxicity is the type most commonly reported. NNRTI treatment is associated with greater durability of the first treatment regimen.

[Analysis of adherence and efficiency when replacing an antiretroviral therapy with efavirenz-emtricitabine-tenofovir in a single daily dose]

OBJECTIVE

To analyse whether the change of antiretroviral therapy to efavirenz/emtricitabine/tenofovir in a single daily dose (EETu) increases adherence and maintains effectiveness, and establish the cost increase caused by the change.

METHODS

An observational, retrospective, and intra-subject study, performed in the outpatient dispensing unit. The study period was 1 year (6 months before and 6 months after the change). Computer dispensing records and days of hospitalisation during the study period were reviewed, and the difference in treatment adherence calculated. To determine the effectiveness of treatment, viral load and CD4 lymphocytes data before and after the change were reviewed. The cost before and after treatment for each patient was determined, and therefore the annual cost increase and the incremental cost per patient.

RESULTS

The study included 127 patients. The difference in adherence was 0.6%. The percentage of poor adherence was 35.4% and 40.9% before and after the treatment change, respectively. The levels of CD4 lymphocytes and viral load did not change significantly with treatment. The economic analysis revealed an annual increase of 25,374.60 and €199.80 per patient.

CONCLUSIONS

The use of EETu did not improve the control of HIV infection in terms of effectiveness and adherence, and resulted in increased economic costs. Therefore, its choice as antiretroviral treatment will have to be based on criteria other than those described above.