Primary or secondary failure of adefovir dipivoxil (ADV) therapy of chronic hepatitis B is not infrequent. The reasons for suboptimal responses are not well defined. In HIV and hepatitis C virus infection, failure of antiviral drug therapy has been linked with low blood drug levels. We have studied 20 well-defined patients with chronic hepatitis B who were treated with ADV for drug and virus kinetics. Importantly, neither Cmax levels (mean 26 ng/mL, range 14-59 ng/mL) nor the time to maximal drug levels (mean 4 h, range 2-8 h) differed between patients showing a complete virological response to adefovir (n = 10), patients with secondary treatment failure (n = 7) and patients with suboptimal primary response (hepatitis B virus-DNA >10 000 IU/mL after 6 months of treatment; n = 3). Thus, adefovir treatment failure is unlikely to be due to an inability to mount sufficient drug levels in the blood.

Hepatitis B, adefovir serum levels, antiviral treatment,
Journal of Viral Hepatitis
Erasmus MC: University Medical Center Rotterdam

Deterding, K, Naesens, L, Buti, M, Janssen, H.L.A, Kirschner, J, Guerrero, A, … Wedemeyer, H. (2011). Adefovir serum levels do not differ between responders and nonresponders. Journal of Viral Hepatitis (Vol. 18). doi:10.1111/j.1365-2893.2010.01404.x