BACKGROUND/AIMS Renal toxicity is a concern in patients with chronic hepatitis B taking nucleotide analogues, such as adefovir (ADV) and tenofovir disoproxil fumarate (TDF). We sought to determine the long-term renal effects of nucleotide analogue treatment versus entecavir (ETV) treatment.

METHODS In this retrospective single-center study, we selected 87 patients who were treated with ADV and subsequently with TDF from June 2008 to December 2013. ETV-treated patients were matched by treatment duration. We analyzed the creatinine increase over 0.5 mg/dL, glomerular filtration rate (GFR) decrease over 25%, phosphorus decrease under 2.0 mg/dL, and dose reduction of antiviral agents.

RESULTS The median follow-up period was 60.0 months for both groups. The incidence of liver cirrhosis was higher in the ADV-TDF group than in the ETV group (32.2% vs 74.7%, p<0.01). Creatinine increased in both groups during follow-up, but the difference was not significant (5.7% and 2.3%, p=0.44). In addition, GFR decreased more often in the ADV-TDF group than in the ETV group (31.0% and 14.9%, p=0.01). After multivariate Cox regression analysis, ADV-TDF treatment was significantly associated with a GFR decrease over 25% (hazard ratio, 2.10; 95% confidence interval, 1.08 to 4.10; p=0.03) after adjusting for the baseline GFR decrease.

CONCLUSIONS Patients taking nucleotide analogues had a significantly higher number of renal events than did those taking ETV. Clinicians should be aware of the development of renal toxicity in this patient population. Further long-term studies are warranted.