Switch from Sodium Phenylbutyrate to Glycerol Phenylbutyrate Improved Metabolic Stability in an Adolescent with Ornithine Transcarbamylase Deficiency
A male patient, born in 1999, was diagnosed with ornithine transcarbamylase deficiency as neonate and was managed with a strict low-protein diet supplemented with essential amino acids, l-citrulline, and l-arginine as well as sodium benzoate. He had an extensive history of hospitalizations for hyperammonemic crises throughout childhood and early adolescence, which continued after the addition of sodium phenylbutyrate in 2009. In December 2013 he was switched to glycerol phenylbutyrate, and his metabolic stability was greatly improved over the following 7 months prior to liver transplant.
KeywordsGlycerol phenylbutyrate Hyperammonemia Ornithine transcarbamylase deficiency Sodium phenylbutyrate Urea cycle disorder
Glycerol phenylbutyrate (Ravicti®) was provided free of charge on a compassionate use basis by Hyperion Therapeutics. Medical writing assistance was provided by Jacqueline Wu, PhD, with funding provided by Horizon Pharma (current license holder of Ravicti®), but this had no influence on the content of the report or on interpretation of data. Alexander Laemmle was supported by competitive research grants from the EMDO Foundation Zurich (Grant 851 to JH and AL) and by the Children’s Research Center – University Children’s Hospital Zurich (Grant 10511 to AL) while working on this study. The work on urea cycle disorders is supported by the Swiss National Science Foundation (grant 310030_153196 to JH).
- Monteleone JP et al (2013) Population pharmacokinetic modeling and dosing simulations of nitrogen-scavenging compounds: disposition of glycerol phenylbutyrate and sodium phenylbutyrate in adult and pediatric patients with urea cycle disorders. J Clin Pharmacol 53(7):699–710CrossRefPubMedPubMedCentralGoogle Scholar