Efficacy and safety of tenofovir double-dose in treatment-experienced HIV-infected patients: The tenoplus study

Fanconi Syndrome in Patients With Human Immunodeficiency Virus Treated With Tenofovir-Based Antiretroviral Therapy: A Systematic Literature Review

OBJECTIVE

Several cases of Fanconi syndrome (FS), a severe form of nephrotoxicity, have been reported in patients with HIV on tenofovir-containing antiretroviral therapy. A systematic review of the published literature on tenofovir-related FS in patients with HIV was conducted.

DATA SOURCES

PubMed and Embase were queried to identify articles in English published between January 2005 and June 2023, reporting tenofovir-related FS in adults with HIV. Preclinical studies, conference/poster abstracts, commentaries and responses, and review papers were excluded.

STUDY SELECTION AND DATA EXTRACTION

Of the 256 articles screened, 57 met the inclusion criteria. These comprised 37 case reports, 11 case series, 1 cross-sectional study, 1 case-control study, 4 cohort studies, 1 single-arm open-label clinical trial, 1 sub-analysis of clinical trials, and 1 pooled analysis of clinical trials.

DATA SYNTHESIS

Among 56 cases on which information was abstracted, median age at FS diagnosis was 50 years, 51.8% were men, and duration of tenofovir use ranged from 6 weeks to 11 years. Ritonavir was co-prescribed in almost half the cases. In observational and interventional studies, incidence of FS was low. Many studies reported resolution of FS symptoms after tenofovir discontinuation. All FS occurrences were identified in those on tenofovir disoproxil fumarate (TDF), except for one patient on tenofovir alafenamide (TAF).

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Continuous monitoring of signs and symptoms of renal and bone toxicity is essential for patients with HIV on tenofovir-containing therapy.

CONCLUSIONS

Occurrence of FS is low in patients with HIV treated with tenofovir-based regimens. Concomitant use of ritonavir may increase risk of FS. TAF may be a safer alternative than TDF in terms of nephrotoxicity.

Role of tenofovir in the treatment of chronic HBV infection

Nucleoside analogues revolutionized the treatment of chronic HBV infection and have become the most important therapeutic option within the last decade. Currently, the nucleoside analogues lamivudine, telbivudine and entecavir, and the nucleotide analogue adefovir dipivoxil, are licensed. Tenofovir disoproxil fumarate (TDF) is another acyclic nucleotide analogue that has been successfully used in the treatment of HIV-infected patients, but has demonstrated significant antiviral activity in wild-type and lamivudine-resistant HBV infections. The use of TDF 300 mg/day leads to marked suppression of HBV replication below the detection limit in different patients groups with HBV mono- or HIV/HBV co-infection in most instances, and a remarkably high rate of hepatitis B e antigen loss and even hepatitis B surface antigen loss was found in small, uncontrolled studies. Belonging to the substance class of acyclic nucleotide analogues, TDF is not cross-resistant to nucleoside analogue resistance-associated mutations. In equal dosages, TDF has comparable antiviral potency as compared with its congender adefovir dipivoxil, but in clinical studies exhibits higher antiviral efficacy and generates a higher genetic barrier against the development of genotypic HBV resistance due to its approximately 24-fold higher dosage. Owing to the numerous newly developed compounds and as a consequence of the emerging problem of drug resistance, treatment concepts for chronic hepatitis B will certainly be modified in the future. Because of its quite favorable antiviral and safety properties, TDF will likely be highly regarded in the management of HBV infections in the future.