Treatment Figure 1. Manifestations of Antiviral Resitance
Antiviral Treatment 8
Virologic Rebound
6
Virologic Breakthrough
4 2 0 -1 0 Years
Serial changes in serum HBV DNA and ALT levels in association with emergence of antiviral-resistant HBV mutants. The first manifestation of antiviral resistance is the detection of resistant mutations (genotypic resistance). Resistant mutations may be detected at the same time or prior to virologic breakthrough (increase in serum HBV DNA by > 1 log10
Table 5. Management of Antiviral-Resistant HBV Prevention
Avoid unnecessary treatment
Initiate treatment with potent antiviral that has a low rate of drug resistance or with combination therapy
Switch to alternative therapy in patients with primary nonresponse Monitoring
Test for serum HBV DNA (PCR assay) every 3-6 months during treatment Check for medication compliance in patients with virologic breakthrough
Confirm antiviral resistance with genotypic testing Treatment
Lamivudine-resistance Adefovir-resistance
Entecavir-resistance Telbivudine-resistanced
a b In HIV coinfected persons; scanty in vivo data in non-HIV infected persons. Truvada® 8
Add adefovir or tenofovir Stop lamivudine, switch to Truvada® a,b
Add lamivudinec Stop adefovir, switch to Truvada® a,b Switch to or add entecavirb,c
Switch to tenofovir or Truvada® b
Add adefovir or tenofovir Stop telbivudine, switch to Truvada®
= combination pill with emtricitabine 200 mg and tenofovir 300 mg.
c Durability of viral suppression unknown, especially in patients with prior lamivudine resistance. d Clinical data not available.
1 2 3
Genotypic Resistance
Hepatitis Flare
Biochemical Breakthrough ULN
(viral rebound) and ALT become abnormal (biochemical breakthrough). In some patients, emergence of antiviral resistance leads to a marked increase in ALT (hepatitis flare).
above nadir). With time, serum HBV DNA levels continue to increase
HBV DNA (Log10 ALT (U/L)
IU/mL)
