Reply to: “Does adherence to hepatitis B antiviral treatment correlate with virological response and risk of breakthrough?”
Authors: Anna S. Lok
Journal: Journal of Hepatology (2011)

Persistence and adherence to nucleos(t)ide analogue treatment for chronic hepatitis BJournal of HepatologyVol. 54Issue 1PreviewLong-term treatment with nucleos(t)ide analogues (NUCs) is associated with increasing rates of antiviral drug resistance. Medication adherence is important in preventing drug resistance. This study aimed to determine, first, the persistence rates and the adherence rates to NUCs in patients with chronic hepatitis B (CHB), and second, the factors associated with adherence. Full-Text PDF Does adherence to hepatitis B antiviral treatment correlate with virological response and risk of breakthrough?Journal of HepatologyVol. 55Issue 6PreviewWe read with interest the study entitled “Persistence and adherence to nucleos(t)ide analogue treatment for chronic hepatitis B” by Chotiyaputta et al. [1]. This study is the first known report in “true life setting” of antiviral drug adherence of HBV patients. Using the US pharmacist providing system, data were collected from 11,100 patients taking HBV antiviral drugs. 55.3% of patients were taking more than 90% of their medication confirming that drug adherence might be better than that observed in HIV patient population [2,3]. Full-Text PDF Open Access We are delighted that Dr. Hilleret and colleagues concur with our finding that in real life clinical practice, adherence to nucleos(t)ide analogs for hepatitis B is less than ideal and has a tendency to decline with time. We agree that the major limitation of our study [[1]Chotiyaputta W. Peterson C. Ditah F.A. Goodwin D. Lok A.S. Persistence and adherence to nucleos(t)ide analogue treatment for chronic hepatitis B.J Hepatol. 2011; 54: 12-18Abstract Full Text Full Text PDF PubMed Scopus (107) Google Scholar] is the inability to correlate our findings with clinical data, but utilizing a nationwide pharmacy database enabled us to study a large number of patients in the community that are more representative than a small cohort of patients in a single tertiary referral center. We congratulate Dr. Hilleret and colleagues in utilizing a direct measure of adherence – serum concentrations of the medication administered, in this case adefovir. We are pleased to see that Dr. Hilleret and colleagues demonstrated a correlation between undetectable concentrations of adefovir in serum and lower rate of virologic response. In a retrospective study of 148 patients receiving nucleos(t)ide analogs for chronic hepatitis B in our clinic, we found that 39 patients had at least one virologic breakthrough during a mean follow-up of 37.5 months [[2]Hongthanakorn C. Chotiyaputta W. Oberhelman K. Fontana R.J. Marrero J.A. Licari T. et al.Virological breakthrough and resistance in patients with chronic hepatitis B receiving nucleos(t)ide analogs in clinical practice.Hepatology. 2011; 53: 1854-1863Crossref PubMed Scopus (108) Google Scholar]. However, only 24 patients had genotypic resistance. Of the 10 patients who experienced virologic breakthrough that was not confirmed on retesting, all 10 had further decrease in serum HBV DNA and nine had undetectable HBV DNA during continued treatment with the same medications. Although adherence was not assessed in that study, these data suggest that medication non-adherence is a common cause of transient virologic breakthrough. Our findings and those of Dr. Hilleret and colleagues highlight the importance of counseling patients with chronic hepatitis B receiving nucleos(t)ide analogs on medication adherence to achieve optimal responses. The authors declared that they do not have anything to disclose regarding funding of conflict or interest with respect to this manuscript.