Measuring ribavirin concentrations during the earliest stages of antiviral therapy for hepatitis C: potential relevance for treatment outcome.

BACKGROUND: Correlations between ribavirin (RBV) concentrations and sustained virological response (SVR) to hepatitis C virus treatment have been demonstrated previously. As steady state is reached after several weeks of RBV treatment, dose modifications based on steady-state levels can only be applied relatively late in treatment, possibly too late to influence SVR rates. The authors aimed to determine whether measurement of early concentrations is useful to predict optimal steady-state RBV concentrations. METHODS: In 61 treatment-naive genotype 1/4 patients RBV concentrations were determined in samples collected after 1, 2, 4, 8, 12, and 24 weeks of therapy. RBV concentrations were compared between responders and nonresponders; Receiver Operating Characteristic analyses were conducted to find optimal cut-off values to predict week 8 concentrations from earlier measurements. RESULTS: Median week 8 RBV concentrations were significantly higher in patients with SVR compared with those without: 3.4 (interquartile range 2.4-3.9) versus 2.6 (interquartile range 2.0-3.5) mg/L (P < 0.05). RBV concentration at week 8 was an independent predictor of SVR [adjusted odds ratio 2.3 (95% confidence interval: 1.1-4.9; P = 0.03)]. The optimal cut-off value of week 8 RBV concentration to predict SVR was 2.20 mg/L [sensitivity 87%, specificity 40%, positive predictive value 64%, negative predictive value 71%]. Optimal cut-off values at weeks 1, 2, or 4 to predict an RBV concentration ≥2.20 mg/L at week 8 were 0.92, 1.29, and 1.67 mg/L, respectively, with positive predictive values and negative predictive values ranging from 88% to 91% and 71% to 86%, respectively. CONCLUSIONS: RBV concentrations in the earliest stages of antiviral therapy predict therapeutic steady-state concentrations, allowing timely dose adjustments with potential implications for treatment outcome.

Patient adherence to antiviral treatment for chronic hepatitis B and C: a systematic review.

INTRODUCTION: Poor adherence to treatment for various chronic diseases is a frequent phenomenon. Current guidelines for the treatment of chronic hepatitis B (HBV) and hepatitis C (HCV) recommend optimal adherence, since it has been suggested that poor adherence is associated with an increased risk of virological failure. We aimed to give an overview of studies exploring adherence to combination treatment (PEG-interferon plus ribavirin) for HCV and nucleos(t)ide analogues for HBV. Material and methods. A systematic review was conducted using the databases PubMed, Embase, Cochrane Library and Web of Knowledge. Search terms included "adherence" or "compliance" combined with "hepatitis B", "hepatitis C" or "viral hepatitis". RESULTS: The final selection included 19 studies (13 HCV, 6 HBV). Large differences in patient numbers and adherence assessment methods were found between the various studies. For HCV mean adherence varied from 27 to 97%, whereas the proportion of patients with ≥ 80% adherence varied from 27 to 96%. Mean adherence reported in HBV studies ranged from 81 to 99%, with 66 to 92% of patients being 100% adherent. For both HCV and HBV studies, the highest adherence rates were reported in studies using self-report whereas lower adherence rates were reported in studies using pharmacy claims. Poor adherence to treatment was associated with an increased risk of virological failure. CONCLUSION: Non-adherence to treatment in chronic viral hepatitis is not a frequent phenomenon. However, given the increased risk of virological failure in poorly adherent patients, clinicians should routinely address adherence issues in all patients treated for chronic viral hepatitis.

Bacterial infections in cirrhosis: role of proton pump inhibitors and intestinal permeability.

BACKGROUND: Cirrhotic patients are at considerable risk for bacterial infections, possibly through increased intestinal permeability and bacterial overgrowth. Proton pump inhibitors (PPIs) may increase infection risk. We aimed to explore the potential association between PPI use and bacterial infection risk in cirrhotic patients and potential underlying mechanisms in complementary patient and animal models. MATERIALS AND METHODS: Bacterial overgrowth was determined in jejunum of 30 rats randomly allocated to 6-week PPI treatment, gastrectomy or no treatment. In 84 consecutive cirrhotic patients, bacterial infection risk was prospectively assessed and related to PPI use. Intestinal permeability was determined by polyethylene glycol (PEG) test in nine healthy individuals and 12 cirrhotic patients. RESULTS: Bacterial overgrowth was much more common in jejunum of rats treated with PPI or gastrectomy compared with nontreated rats. Twenty-four patients (29%) developed a bacterial infection during a median follow-up of 28 months. Although PPI users tended to experience infection more often than patients without PPI therapy, PPI use was not an independent predictor of bacterial infection (HR 1·2, 95% CI 0·5-3·0, P = 0·72), after correction for Child-Pugh class (HR 3·6, 95% CI 1·5-8·7, P = 0·004) and age (HR 1·05, 95%CI 1·01-1·09, P = 0·02). In cirrhotic patients, 24-h urinary recovery of PEGs 1500 and 3350 was significantly higher compared with healthy controls. CONCLUSIONS: Although in our animal model PPIs induced intestinal overgrowth, stage of liver disease rather than PPI use was the predominant factor determining infection risk in cirrhotic patients. Increased intestinal permeability may be a factor contributing to infection risk.

Adherence to ribavirin in chronic hepatitis C patients on antiviral treatment: Results from a randomized controlled trial using real-time medication monitoring.

BACKGROUND AND OBJECTIVE: Adherence is essential in antiviral therapy for chronic hepatitis C. We investigated the effect of real-time medication monitoring on adherence to ribavirin. METHODS: In this randomized controlled trial, patients in the intervention group received a medication dispenser that monitored ribavirin intake real-time during 24 weeks PEG-interferon/ribavirin±boceprevir or telaprevir. Patients in the control group received standard-of-care. Adherence was also measured by pill count. RESULTS: Seventy-two patients were assigned to either intervention (n=35) or control groups (n=37). Median adherence by pill count was 96% (range: 43%-100%) with 30 (94%) of patients exhibiting≥80% adherence. Perfect adherence (i.e. 100%) was similar in intervention and control groups: 22 (85%) vs. 15 (75%) (P=0.47). Adherences by real-time medication monitoring and by pill count did not correlate (R=0.19, P=0.36). No predictors of poor adherence could be identified. Ribavirin trough levels after 8 weeks (median: 2.4 vs. 2.7mg/L, P=0.30) and 24 weeks (median: 3.0 vs. 3.0mg/L, P=0.69), and virological responses did not differ between intervention and control groups. CONCLUSIONS: Adherence to ribavirin during PEG-interferon containing therapy in chronic hepatitis C is high. Real-time medication monitoring did not influence adherence to ribavirin, plasma ribavirin levels or virological responses.

Real life adherence of chronic hepatitis B patients to entecavir treatment.

BACKGROUND: Real-life prospective data on adherence to nucleos(t)ide analogues in chronic hepatitis B patients are scarce. AIMS: We investigated adherence to entecavir in relation to virological response. METHODS: In this prospective study, we provided 100 consecutive chronic hepatitis B patients with a medication dispenser that monitored entecavir intake during 16 weeks therapy. Hepatitis B virus (HBV) DNA was measured at baseline and after 16 weeks. Beliefs about medicines were evaluated using a questionnaire. RESULTS: Adherence over 16 weeks averaged 85 ± 17%, with 70% of patients exhibiting good (i.e. ≥ 80%) adherence. Patients with poor (i.e. <80%) adherence were significantly younger (p=0.01), with more often indifferent attitudes towards entecavir (p=0.03) Viral breakthrough did not occur during the study. Adherence in patients with HBV DNA after 16 weeks > 20 IU/mL (n=18) and ≤ 20 IU/mL (n=81) averaged 83% and 91% respectively (p=0.19). In multivariate analysis, adherence was not a significant predictor of HBV DNA negativity (adjusted OR 1.02; p=0.34), after adjustment for duration of entecavir treatment (p<0.001) and HBe-status (p=0.001). CONCLUSIONS: 70% of chronic hepatitis B patients exhibited good adherence to entecavir, with younger age and an indifferent attitude being risk factors for poor adherence. Poor adherence was not an independent predictor of virological response.

The "Von Meyenburg complex": an unusual cause of cholangitis?

Von Meyenburg complexes are an unusual incidental finding at radiologic or pathologic evaluation of patients with suspected liver disease. We present a case report of a patient with recurrent septic episodes in whom von Meyenburg complexes were eventually diagnosed and discuss available literature on this topic.

Suboptimal endogenous erythropoietin response in chronic hepatitis C patients during ribavirin and PEG interferon treatment.

BACKGROUND: During the treatment of hepatitis C, anaemia may necessitate pegylated-interferon and ribavirin dose reductions with reduced sustained viral response rates. Although erythropoietic growth factors are frequently used to improve anaemia, it is controversial whether endogenous erythropoietic response is insufficient under these circumstances. We aimed to identify risk factors for more pronounced anaemia and to evaluate endogenous erythropoietic response during antiviral therapy. METHODS: One hundred and forty-five naive chronic hepatitis C patients on pegylated-interferon-ribavirin treatment were evaluated for haemoglobin, haematocrit, serum ribavirin and erythropoietin levels. RESULTS: About 99% of patients developed anaemia, with maximal decrease in haemoglobin of 2.5 ± 1.0 mmol/l (range 0.3-5.5 mmol/l). Older age, lower baseline creatinine clearance, higher baseline haemoglobin, more pronounced haemoglobin decrease after 2 weeks and higher week 24 serum ribavirin concentrations were independent risk factors for more pronounced anaemia. Serum erythropoietin levels increased from median 12 IU/l (range 4-63 IU/l) at baseline to 41 IU/l (range 12-683 IU/l) after 12 weeks of therapy and to 43 IU/l (range 7-3238 IU/l) at week 24 (P<0.001). Erythropoietin levels at baseline, week 12 and week 24 negatively correlated with haematocrit. The erythropoietic response to anaemia in our study population was significantly different from the normal human response to anaemia. CONCLUSION: Older age, lower baseline creatinine clearance, higher baseline haemoglobin, more pronounced haemoglobin decrease after 2 weeks and higher week 24 serum ribavirin concentrations were independent risk factors for more pronounced anaemia during antiviral therapy. Endogenous erythropoietin production is suboptimal during antiviral therapy, supporting use of erythropoietic growth factors.