University of California at San Diego, San Diego, California, USA.
BACKGROUND AND AIMS:
Tenofovir is a nucleotide reverse-transcriptase inhibitor approved for treatment of HIV infection, as well as chronic hepatitis B (CHB). We evaluated nephrotoxicity among patients with CHB treated with tenofovir.
We performed a community-based, retrospective cohort study of 80 patients with CHB who received tenofovir, alone or in a combination regimen; they were matched for age and sex with 80 CHB patients who received only entecavir. Incidences of serum creatinine (SCr) increase ≥ 0.2 mg/dL and new SCr levels of 1.5, 2.0, or 2.5 mg/dL were assessed. Patients with an estimated glomerular filtration rate (eGFR) < 60 mL/min, calculated using the Modification of Diet in Renal Disease (MDRD) or Cockcroft-Gault (CG) formula, or who had ≥ 20% decrease in eGFR were also recorded.
More patients given entecavir had increases in SCr ≥ 2.5 mg/dL (1 vs 6;P = .053), whereas more patients given tenofovir had a new CG eGFR of < 60 mL/min (15 vs 6; P=.022) and at least one dose adjustment (13 vs 4;P =.021). By multivariate analysis, the only significant factors associated with an increase in SCr were a history of organ transplantation (adjusted odds ratio [OR] 6.740; 95% confidence interval [CI], 1.799 - 28.250;P =.005) and pre-existing renal insufficiency (adjusted OR 10.960; 95% CI, 2.419 - 48.850;P =.002). No factors, including therapy assignment, were associated with a new eGFR < 60 ml/min.
Markers of renal function indicated that patients who received tenofovir were no more likely to have changes in renal function than patients treated with entecavir. History of transplant and pre-existing renal insufficiency were the only factors independently associated with increases in SCr.