Renal safety of tenofovir and/or entecavir in patients with chronic HBV monoinfection.

Background: Tenofovir disoproxil fumarate (TDF) and entecavir (ETV) are recommended as the first-line therapy for chronic hepatitis B (CHB) due to their genetic barrier to resistance and effectiveness of virological suppression. TDF and ETV may cause renal toxicity through various mechanisms such as renal tubular injury, apoptosis, and mitochondrial toxicity. The aims of the current review were to assess the potential renal toxicity associated with the use of TDF and ETV in patients infected with chronic hepatitis B virus (HBV) and to provide clinical perspectives on these two agents in the treatment of CHB.

Methods: A literature search of clinical studies published in PubMed and posted on ClinicalTrials.gov website was implemented to find studies evaluating the potential renal toxicity of TDF and ETV.

Results: Twenty-one studies were examined in this review. The TDF dose used in the studies was 245 or 300 mg/day and that of ETV was 0.5 or 1 mg/day. Based on the markers of renal function, patients treated with TDF were not more likely to show changes in renal function than those treated with ETV; however, the estimated glomerular filtration rates (eGFRs) of patients receiving TDF tended to be more clearly reduced than those of patients receiving ETV. The eGFRs of patients treated with TDF decreased in a time-dependent manner, whereas those of patients treated with ETV increased or decreased across various time points.

Conclusion: The data shown in this study suggest that use of TDF and ETV could be at least associated with reductions in renal function in patients with chronic HBV infection. However, various risk factors, such as pre-existing renal failure and comorbidities, are also associated with decreased renal function during the treatment of TDF and ETV. Thus, studies of management strategies for HBV-infected patients with these risk factors are necessary in the near future.