Incidence and associated risk factors of nephrotoxicity due to Tenofovir in HIV-infected patients

Abstract

The current HIV treatment guideline in Thailand has included Tenofovir (TDF) in the first-line regimen (alongside Lamivudine (3TC) and Efavarenz (EFV) for treating HIV-infected patients in almost all age groups. Yet, there have been few studies that explore incidence of TDF-related nephrotoxicity as well as its risk factors in actual clinical practice in the Thai context. The objective of this study was to assess the incidence and associated risk factors of nephrotoxicity in HIV-infected patients which would be important and benefitial for the improvement of quality of care in HIV treatment. It was conducted at Somdejphrajaotaksin-Maharaj Hospital, Tak province. Retrospective cohort study design was employed. Three hundred and forty four HIV-infected cases were investigated. Among them, 79 cases were treated with TDF. Data analysis was performed by both descriptive statistics using means and percentage, and inferential statistics using multiple logistic regression and generalized linear model with robust error variance. It was found that the incidence of nephrotoxicity within 12 months of TDF treatment was approximately 26.6%; while the non-TDF cases had nephrotoxicity incidence at about 4.9%. After adjusting for confounding effects of all potential risks, TDF seemed to increase nephrotoxicity risk by 5 to 7 folds, compared to the non-TDF patients. Note that the nephrotoxicity risk by TDF seemed to be more apparent (up to 12 to 15 folds) within the first 6 months of treatment. Other relevant risk factors identified included being female and having chronic non-communicable diseases. However, the study still faced some keylimitations, for instance, lack of randomization and short study period. In summary, the study had complemented the state-of-the-arts in care management for HIV-infected patients in Thailand. The findings could benefit actual clinical practice by introducing more rigorous monitoring measures for TDF-treated cases, particularly within the first 6 months of treatment, and amongst those with chronic non-communicable diseases.