Table 8.
Antiviral Resistance by Genotypic Testing | Switch Strategy (Preferred) | Add Strategy: 2 Drugs Without Cross-Resistance |
---|---|---|
Lamivudine resistance | Tenofovir* (TDF or TAF) | Continue lamivudine; add tenofovir (TDF or TAF) (or alternative emtricitabine-tenofovir) |
Telbivudine resistance | Tenofovir* (TDF or TAF) | Continue telbivudine; add tenofovir (TDF or TAF) |
Adefovir resistance | Entecavir or Tenofovir* (TDF or TAF) | Continue adefovir; add entecavir |
Entecavir resistance | Tenofovir* (TDF or TAF) | Continue entecavir; add tenofovir (TDF or TAF) or alternative emtricitabine-tenofovir |
Tenofovir resistance | Entecavir* | Continue tenofovir (TDF or TAF) and add entecavir |
Multidrug resistance | Tenofovir | Combined tenofovir (TDF or TAF) and entecavir* |
Efficacy appears similar with switching to an antiviral with high genetic barrier to resistance and without cross-resistance versus combination therapy with follow-up periods to 5 years. Thus, switching is the preferred strategy except if HBV is multidrug resistant.