Sodium Benzoate
Synonym :
Sodium Benzoate/Sodium Phenylacetate
Mechanism :
Sodium benzoate is a metabolically active compound that can serve as alternatives to urea for the excretion of waste nitrogen. Preceded by acylation, benzoate conjugates with glycine to form hippuric acid, which is rapidly excreted by the kidneys by glomerular filtration and tubular secretion.
Indication :
- Hyperammonemia
- Urea cycle defects
- Nonketotic hyperglycinemia
Contraindications :
Should not be administered to patients with known hypersensitivity to sodium benzoate. High sodium content therefore use in caution in patients with congestive heart failure or severe renal insufficiency and in clinical states where there is sodium retention with edema.
Dosing :
Hyperammonemia:
Oral: 250 mg/kg/day in 4 divided doses.
Acute hyperammonemia and associated encephalopathy in patients with deficiencies in enzymes of the urea cycle:
>20 kg:
5.5 g/m² of sodium phenylacetate and 5.5 g/m² of sodium benzoate IV loading dose through a central line over 90 to 120 minutes, then give the same dose over 24 next hours.
<20 kg:
250 mg/kg of sodium phenylacetate and 250 mg/kg of sodium benzoate IV loading dose through a central line over 90 to 120 minutes, then give the same dose over 24 next hours.
Non-ketotic hyperglycinemia:
New-born: 250 mg/kg/day oral in 4 divided doses.
>1 month: 500 mg/kg/day oral in 4 divided doses.
Adverse Effect :
Most commonly seen adverse effect is vomiting. It can be helped by giving smaller doses more frequently or giving with food/feed. Anorexia, irritability, lethargy and coma can occur when high doses are given. Toxicity is more likely in neonates due to incomplete conjugation.
Interaction :
No significant interactions found.
Hepatic Dose :
Use with caution; further studies pending.