Background: The incidence and risk factors for adefovir-resistant HBV have not been clearly defined. Aims: To characterize the virologic response to adefovir, to determine the rate of adefovir resistance and to explore factors associated with initial virologic response (IVR) and adefovir resistance. Methods: All hepatitis B patients who received adefovir for ≥6 months at our center were prospectively monitored for virologic response and adefovir resistance. Results: Forty three patients were included; mean treatment duration was 18 months (range 6-45). Thirty four (79%) patients had prior lamivudine. IVR was observed in 44% patients and associated with higher pretreatment ALT (P=0.05) and the absence of HBeAg (P=0.02). Six (14%) patients were found to have adefovir-resistant mutations. The cumulative probability of genotypic resistance to adefovir at month 24 was 22%. Patients with adefovir resistance were more likely to have been switched from lamivudine to adefovir monotherapy (P=0.01), to be older (P=0.04), and to be infected with HBV genotype D (P=0.02). Conclusions: Roughly 50% of patients failed to achieve IVR on adefovir. The cumulative probability of adefovir resistance at 2 years was 22%. Our data suggest that combination of lamivudine and adefovir may prevent emergence of adefovir resistance in patients with lamivudine-resistant HBV.
|Original language||English (US)|
|Number of pages||8|
|Journal||Journal of Hepatology|
|State||Published - Feb 2006|
- Antiviral resistance
- Hepatitis B
ASJC Scopus subject areas