Trade Name of Sodium Benzoate
The intravenous formulation of sodium benzoate is available as Ammonul (manufactured by Ucyclyd Pharma), which is a combination product containing sodium phenylacetate and sodium benzoate 1, 2. Additionally, sodium benzoate is available as Caffeine and Sodium Benzoate Injection, USP, where sodium benzoate is added to increase the solubility of caffeine 3.
Clinical Context
For hyperammonemia treatment specifically, Ammonul is the primary trade name formulation used. This product delivers both nitrogen-scavenging agents (sodium phenylacetate and sodium benzoate) together in a single intravenous preparation 2. The combination has demonstrated 84% overall survival in 299 patients with urea cycle disorders across 1,181 episodes of acute hyperammonemia 2.
Dosing Formulations
Ammonul: Contains equal parts sodium phenylacetate and sodium benzoate for intravenous administration in hyperammonemic crises 1, 2
Caffeine and Sodium Benzoate Injection, USP: Contains 125 mg caffeine (anhydrous) and 125 mg sodium benzoate per mL, primarily used as a CNS stimulant rather than for ammonia scavenging 3
Important Clinical Considerations
When sodium benzoate is used for hyperammonemia, the recommended dosing from consensus guidelines is 4:
- <20 kg body weight: 250 mg/kg
- >20 kg body weight: 5.5 g/m²
- Maximum daily dose: 12 g (high-dose benzoate can be toxic and lethal within 1 hour)
- Administration: Given over 90 minutes as bolus, then as maintenance over 24 hours
Critical safety note: The pharmacokinetics of benzoate show saturable, non-linear elimination with decreased clearance at higher doses 1. Benzoate plasma levels fall rapidly after the priming dose and become undetectable within 14-26 hours depending on dose 1. This differs significantly from phenylacetate, which has slower elimination and requires careful monitoring to avoid toxicity.