sodium phenylacetate and sodium benzoate

Disclaimer to the Online Edition

This Manual has been designed for use in the NICU at London Health Sciences Centre (LHSC), London, Ontario, Canada, and represents clinical practice at this institution. The information contained within the Manual may not be applicable to other centres. If users of this Manual are not familiar with a drug, it is recommended that the official monograph be consulted before it is prescribed and administered. Any user of this information is advised that the contributors, Editor and LHSC are not responsible for any errors or omissions, and / or any consequences arising from the use of the information in this Manual.

sodium phenylacetate and sodium benzoate (Ammonul ®) (Special Access Medication) *

Indication

  • Adjunct to treatment of acute hyperammonemia and encephalopathy in patients with urea cycle disorders

Dosage Guidelines

Acute hyperammonemia

  • Loading dose: 250 mg/kg IV in combination with arginine hydrochloride 600 mg/kg over 90 minutes
  • Maintenance dose: 250 mg/kg IV in combination with arginine hydrochloride 600 mg/kg over 24 hours as a continuous infusion

Administration

  • Administer through a central line (preferred) or large peripheral vein
  • Loading dose: slow IV infusion over 90 minutes
  • Maintenance dose: IV continuous infusion

Adverse Effects

  • The most common adverse effects include: vomiting, hyperglycemia and hypokalemia
  • Other less common adverse effects include: Hypotension (more common in neonates), bradycardia, cardiomyopathy, rash, anemia, cholestasis and pneumothorax

Comments

  • Peripheral line administration may cause burns
  • Extravasation may result in skin necrosis
  • This medication is excreted in the urine and feces, and can be irritating, early application of a barrier ointment to the perineum is recommended
  • This medication has a strong, unpleasant odour
  • If your hands or other skin areas come in contact with the solution it is recommended to clean your hands with sodium bicarbonate.
  • Dialysis is recommended in patients who fail to significantly respond after 4-8 hours after initiating treatment.
  • Use with caution in patients with renal or hepatic dysfunction
  • Do NOT mix with other infusion solutions

Supplied As

  • Dose as ordered in a volume of Dextrose 10% providing a final volume of 30-35 mL/kg
  • * Pharmacy maintains a future use supply of sodium phenylacetate and sodium benzoate -approval through the Special Access Program is not required prior to initiation
References
  1. LexiComp Sick Kids
  2. LexiComp Pediatric and Neonatal
  3. Neofax