Renal Concerns in the Treatment of Chronic Hepatitis B with Tenofovir

Abstract

Tenofovir, a third generation oral nucle(t)oside analogue, currently represents one of the first-line drugs recommended for treating chronic hepatitis B (HBV) infection. After oral administration, Tenofovir is mostly excreted in the urine by glomerular filtration and proximal tubular secretion. Hence, an impaired kidney function may lead to an increased renal exposure to the drug in patients with co-existent renal damage. This could further worsen kidney disease through different mechanisms of nephrotoxicity such as mitochondrial DNA depletion and tubular cytotoxicity. Despite several studies have been performed so far to assess Tenofovir-related renal toxicity, data in HBV patients are not yet conclusive. Screening of risk factors for kidney disease before starting therapy and a careful monitoring of serum creatinine, glomerular filtration rate, serum phosphate and urine analysis during treatment are advocated in patients treated with Tenofovir, in order to adjust the dose or stop treatment if needed. New biomarkers of tubular injury, such as NGAL, could become helpful in the next future for the timely identification and risk stratification of renal damage induced by this therapy.