Predictors of pruritus in patients with chronic liver disease and usefulness of nalfurafine hydrochloride

Abstract

Aim: Pruritus is one of the complications of chronic liver disease, and it is important to investigate the predictors.

Methods: Six hundred and seventy-three consecutive Japanese patients with chronic liver disease were retrospectively investigated for itch severity. Furthermore, 138 of all 673 patients were introduced to nalfurafine hydrochloride, and the improvement of itch severity was evaluated. The itch severity was self-assessed using the pruritus scores by Kawashima's criteria and visual analog scale.

Results: Two hundred and twenty-nine of the 673 patients (34.0%) were evaluated as 1 point or more of pruritus severity of Kawashima's criteria, and 46 patients (6.8 %) as 3 points or more. Multivariate analysis established that being negative for hepatitis B surface antigen (HBsAg) and presence of hepatocellular carcinoma (HCC) were significant determinants of pruritus (≥1 point of Kawashima's criteria), and being negative for HBsAg and having lower levels of platelet count were significant determinants of severe pruritus (≥3 points). Ninety-three of the 138 patients (67.4%) with nalfurafine hydrochloride indicated improvement of itch, defined as a decrease in VAS of 50 mm or more. There were no significant differences in treatment efficacy of nalfurafine hydrochloride, regardless of the three predictors of pruritus (HBsAg, HCC and platelet count).

Conclusion: The present retrospective study indicated the predictors for pruritus, based on the large number of patients with chronic liver disease. Furthermore, this study demonstrated that nalfurafine hydrochloride may be useful for pruritus, regardless of the predictors.

Keywords: Kawashima's criteria; hepatitis B virus; hepatocellular carcinoma; nalfurafine hydrochloride; platelet count; pruritus; visual analog scale; κ-opioid receptor agonist.