Anti-HCV treatment with ombitasvir/paritaprevir/ritonavir ± dasabuvir is associated with increased bile acid levels and pruritus

Direct acting antiviral (DAA)-based treatment with ombitasvir/paritaprevir/ritonavir ± dasabuvir (OBV/PTV/r ± DSV) is highly effective in HCV genotype 1 or 4 infection and well-tolerated with only few side effects. However, pruritus has been observed in several trials in up to 20% of patients and seems to be unique for this DAA combination.

The aim of this preliminary study was to investigate the effect of OBV/PTV/r ± DSV on bile acid levels and to correlate them to the emergence of pruritus during treatment.

Twenty patients with chronic hepatitis C genotype 1 or 4 were treated for 12 or 24 weeks with OBV/PTV/r ± DSV with or without ribavirin. Side effects including pruritus were assessed every 4 weeks during treatment or on demand. Blood was collected in fasting state at baseline and at treatment week 4 for determination of bile acid concentrations by high-resolution mass spectrometry.

Pruritus developed in 5 out of 20 patients during the first 4 weeks of DAA treatment. Pruritus was self-limiting during DAA treatment in 4 patients while one patient required cholestyramine treatment and responded well. Total bile acid levels increased approximately 4‑fold by treatment week 4.

Pruritus observed during OBV/PTV/r ± DSV treatment of chronic hepatitis C is associated with increased on-treatment serum bile acid levels, possibly due to ritonavir-induced alterations of bile acid transport.