sodium benzoate/sodium phenylacetate

Action and Spectrum

Actions and Spectrum 

sodium benzoate works by reducing the pH of the food, making it acidic and creating an unfavourable environment for microbial growth. sodium benzoate is effective against a broad spectrum of microorganisms, including bacteria, yeasts, and molds.  

sodium phenylacetate works by conjugating with another compound called glutamine to form phenylacetylglutamine, which can be excreted from the body, helping to eliminate excess nitrogen. sodium phenylacetate is primarily used for its therapeutic effects in specific metabolic disorders.   

Drug Interaction

Adverse Reaction

Frequency defined  

1-10% 

Convulsions (6%) 

Diarrhea (3%) 

Respiratory distress (3%) 

Pyrexia (5%) 

Hyperammonemia (5%) 

Acidosis (3%) 

Hypotension (4%) 

Mental impairment (6%) 

Nausea (3%) 

Brain edema (5%) 

Skin disorder (6%) 

UTI (3%) 

Hypocalcemia (3%) 

Coma (3%) 

Hyperglycemia (7%) 

Agitation (3%) 

DIC (3%) 

Anemia (4%) 

>10% 

Vomiting (12%) 

Black Box Warning

Black Box Warning 

None

Contraindication / Caution

Contraindication/Caution: 

Contraindication: 

• Individuals who have a known hypersensitivity or allergy to sodium benzoate/sodium phenylacetate should avoid its use. 

Caution: 

• Individuals with underlying health conditions such as liver or kidney disease may need to exercise caution.  
• stop taking oral anti-hyperammonemic drugs before administration. 

Pregnancy / Lactation

Pregnancy consideration: 

Pregnancy category: N/A 

Lactation: Excretion into human milk is unknown  

Pregnancy Categories:         

Category A: well-controlled and Satisfactory studies show no risk to the fetus in the first or later trimester. 

Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women.  

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women. 

Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits. 

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women. 

Category N: There is no data available for the drug under this category. 

Pharmacology

Pharmacology  

sodium benzoate acts by inhibiting the growth of bacteria, yeasts, and molds through its ability to acidify the environment. It enters microbial cells where it disrupts cellular function and inhibits various metabolic pathways. sodium phenylacetate helps remove excess nitrogen from the body by facilitating the excretion of phenylacetylglutamine in the urine. 

Pharmacodynamics 

Because it lowers the pH of the surroundings, sodium benzoate has antibacterial properties. The benzoic acid separates out as sodium ions and a weak acid, lowering the pH of the medium. 

sodium phenylacetate affects the urea cycle, which is responsible for the detoxification of ammonia in the body. It helps bypass certain steps of the urea cycle and promotes alternative pathways for the elimination of nitrogen. 

Pharmacokinetics 

Absorption   

sodium benzoate/sodium phenylacetate both are well absorbed from the gastrointestinal tract. 

Distribution 

sodium benzoate/sodium phenylacetate both distributes widely throughout the body and crosses the blood-brain barrier. 

Metabolism 

In the liver, sodium benzoate is metabolized via conjugation with glycine to form hippuric acid.  

In the liver, sodium phenylacetate undergoes conjugation with glutamine by the enzyme phenylacetyl-CoA: glutamine N-acyltransferase. 

Elimination and excretion 

The route of elimination for sodium benzoate/sodium phenylacetate is through the kidneys. 

Adminstartion

Administration 

sodium benzoate is commonly administered orally. It is available in various forms such as tablets, capsules, or as a liquid solution.  

sodium phenylacetate is typically administered intravenously. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: sodium benzoate/sodium phenylacetate 

Why do we use sodium benzoate/sodium phenylacetate? 

sodium phenylacetate/sodium benzoate are used in the treatment of urea cycle deficiency (UCDs).  

sodium benzoate is used as a preservative in various food and beverage products. It helps inhibit the growth of bacteria and yeasts.  

sodium phenylacetate helps remove excess nitrogen from the body by promoting the excretion of phenylacetylglutamine in the urine.