Adefovir-related nephrotoxicity by adefovir dose-reduction in HBV

A study in the latest issue of Alimentary Pharmacology & Therapeutics investigates resolution of adefovir-related nephrotoxicity by adefovir dose-reduction in patients with chronic hepatitis B.

Chronic hepatitis B patients treated with adefovir were followed up to evaluate nephrotoxicity and its outcome.

Dr Hartono and colleagues assessed the incidence of renal dysfunction during adefovir therapy in Asian patients and factors associated with it.

The team evaluated strategies to improve adefovir-related renal dysfunction, and their impact on viral suppression.

The researchers evaluated chronic hepatitis B clinic patients from a tertiary hospital on adefovir treatment.

The team extracted clinical and laboratory parameters from the hospital electronic clinical database in an observational study design.

Patients were excluded if they had liver/renal transplant, baseline renal impairment or were on dialysis.

The team of doctors defined adefovir-related renal dysfunction as adefovir-related abnormal serum creatinine as 125 μmol/L, 90 μmol/L for adefovir-related abnormal GFR 60 mL/min, and adefovir-related increased serum creatinine as 0.5 mg/dL, without other known causes of nephrotoxicity.

A total of 271 out of 383 adefovir-treated patients were suitable for analysis, and 33 patients developed abnormal serum creatinine.

Adefovir-related abnormal serum creatinine was 34%

Alimentary Pharmacology & Therapeutics

The research team found that cumulative increase in proportion of patients with adefovir-related abnormal serum creatinine was 34% and adefovir-related abnormal 60 mL/min was 38% by 6 years, while serum creatinine increase 0.5 mg/dL was 22% by 5 years.

Using multivariate analysis, the only independent baseline predictor of adefovir-related abnormal serum creatinine was adefovir-related abnormal 76.1 mL/min.

The team of doctors noted that patients who had adefovir-related abnormal serum creatinine had similar levels of viral suppression to those who did not have adefovir-related abnormal serum creatinine.

Those who had adefovir-related abnormal serum creatinine either continued adefovir, switched therapy or had adefovir dose reduction.

The researchers reported that adefovir-related abnormal serum creatinine resolved and adefovir-related abnormal normalised in almost all patients after either switching therapy or reducing adefovir dose, with no difference between the two strategies.

Those with adefovir dose reduction had no significant increase in HBV DNA.

Dr Hartono and his team commented, "Adefovir-related renal dysfunction occurred in a significant number of adefovir-treated patients, but reduction of the dose led to renal improvement without compromising treatment efficacy."