Neonatal Drug Therapy Manual


Disclaimer: Official controlled document is the CHEO and Ottawa Hospital online copy. It is the responsibility of user to ensure that any paper copy version is the same as the online version before use.

Alternate Name(s): 
Sodium Benzoate/Sodium Phenylacetate
Urea Cycle Disorder (UCD) Treatment Agent
Original Date: 
Sept 2022
  • Acute treatment of hyperammonemia associated with urea cycle disorders
  • IV Intermittent Infusion: central line 
    Infusion time: 90 minutes

  • IV Continuous Infusion: central line 

  • Loading: 250 mg/kg/dose IV as a loading dose. Give IV over 90 minutes
  • Maintenance: Followed by 250 mg/kg/day as a continuous IV infusion
Side Effects: 
  • IV infiltration may cause necrosis and phlebitis
  • Nausea, vomiting (especially with loading dose)
  • Hypotension
  • Metabolic acidosis, hyperglycemia, hypokalemia, hypocalcemia, hyperammonemia, hypernatremia
  • Seizure, cerebral edema, agitation
Parameters to Monitor: 
  • Monitor plasma ammonia levels, neurological status, blood gases

  • Electrolytes and glucose 

  • LFTs and renal function (use with caution in renal or hepatic impairment)

Reconstitution and Stability: 


  • Available from pharmacy as a 10 mg/mL solution in D10W, with or without Arginine HCL* added. 

*see monograph for Arginine HCL 

  • Solutions Compatible: D10W ONLY
  • Additive/Above Cassette Compatible: arginine HCL, sodium bicarbonate
  • Y-site Compatibility: arginine HCL, sodium bicarbonate
  •  For 250 mg/kg Ammonul® and 600 mg/kg Arginine HCL dosing, use Ammonul® 10 mg/mL with Arginine HCL 24 mg/mL in D10W.

  • Fluid overload: Use with caution in patients at risk for fluid overload (eg, heart failure, severe renal impairment) or sodium retention edema; contains a significant amount of sodium (Ammonul® vials of 100 mg/mL contains 0.52 mmol of sodium/mL)
  • Caution in neonates: displaces bilirubin from protein-binding site
  • Enhanced potassium excretion may occur with treatment of hyperammonemia, monitor serum potassium concentration closely. 
  • Lexi-Comp Online Database, accessed Sept 2022
  • Ammonul Product Monograph 

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