Switching patients with lamivudine resistant chronic hepatitis B virus from tenofovir to adefovir results in less potent HBV-DNA suppression

Authors


Robert A. de Man MD, PhD, Department of Gastroenterology and Hepatology, room H437, Erasmus University Medical Center Rotterdam, ‘s Gravendijkwal 230, 3015 CE Rotterdam, The Netherlands. E-mail: r.deman@erasmusmc.nl

Abstract

Summary.  The nucleotide analogues, tenofovir disoproxil fumarate and adefovir dipivoxil, inhibit viral replication and are both effective against the hepatitis B virus (HBV). In our department, tenofovir was prescribed in addition to lamivudine for the treatment of lamivudine resistant chronic hepatitis B. After registration of adefovir, 10 patients were switched to adefovir monotherapy. We studied changes in HBV-DNA and alanine aminotransferase (ALT) in these patients. The median treatment duration with tenofovir was 78 weeks resulting in a median viral load reduction of 5.4 (range 6.8–2.3) log10 copies/mL compared to baseline (P = 0.005). Two patients had an increase >1 log10 copies/mL during tenofovir treatment. After the switch to adefovir, six out of 10 patients had an HBV-DNA >4 log10 copies/mL and the median HBV-DNA increased from 2.8 to 4.5 log10 copies/mL (P = 0.017). The factors associated with relapse were HBV-DNA PCR positivity at the time of switch and genotype B or D. ALT levels at the beginning of tenofovir treatment also might be a factor. Retreatment with tenofovir (n = 3) resulted in a rapid decline in HBV-DNA. Tenofovir is a potent antiviral drug. Switching to adefovir resulted in viral relapse in 60% of patients and retreatment with tenofovir resulted again in viral decline, which suggests that tenofovir is a more potent antiviral agent.

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