Depending on clinical status and the blood ammonia level, the logical first step is to reduce protein intake and to attempt to maintain energy intake. Initiate intravenous infusion of 10% glucose (or higher, if administered through a central line) and lipids. Intravenous sodium benzoate and sodium phenylacetate may be helpful. Arginine is usually administered with benzoate and phenylacetate. This is best administered in the setting of a major medical center where facilities for hemodialysis in infants is available. Glycerol phenylbutyrate is a pre-prodrug that undergoes metabolism to form phenylacetate. Results of a phase 3 study comparing ammonia control in adults showed glycerol phenylbutyrate was noninferior to sodium phenylbutyrate. In a separate study involving young children ages 2 months through 5 years, glycerol phenylbutyrate resulted in a more evenly distributed urinary output of PAGN over 24 hours and accounted for fewer symptoms from accumulation of phenylacetate. In patients with an extremely high blood ammonia level, rapid treatment with hemodialysis is indicated. Metabolic disease specialists should provide long-term care with very close and frequent follow-up.
Carbamoyl phosphate synthetase I deficiency
Malonyl-CoA decarboxylase deficiency
Holocarboxylase synthetase deficiency
Aminoacylase 1 deficiency
Pyruvate kinase deficiency
2,4 Dienoyl-CoA reductase deficiency
Guanidinoacetate methyltransferase deficiency
Arginine:glycine amidinotransferase deficiency