What is the role of glycerol phenylbutyrate (GPB) in the treatment of hepatic encephalopathy (HE)?

Updated: May 18, 2020
  • Author: David C Wolf, MD, FACP, FACG, AGAF, FAASLD; Chief Editor: BS Anand, MD  more...
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In a phase II trial involving 178 patients with cirrhosis (including 59 already taking rifaximin) who had experienced two or more hepatic encephalopathy (HE) events in the previous 6 months, glycerol phenylbutyrate (GPB), at a dose of 6 mL orally twice-daily, significantly reduced the proportion of patients who experienced an HE event, time to first event, and total events. [66] In addition, GPB was associated with fewer HE hospitalizations. For patients not on rifaximin at enrollment, GPB reduced the proportion of patients with an HE event, time to first event, and total events. Plasma ammonia was significantly lower in patients on GPB than in patients on placebo. Adverse events occurred in a similar proportion of patients in the GPB and placebo groups. The authors concluded that the results implicated ammonia in the pathogenesis of HE and suggested that GPB had therapeutic potential in this patient population. [66]

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