Adult Dosing

Acute hyperammonemia

• 55 mL/m² IV over 90-120 mins, followed by an equivalent maintenance infusion given over 24 hrs

• Provides 5.5 gm² sodium phenylacetate/5.5 gm² sodium benzoate
• Therapy should be stopped when hyperammonemia is resolved and oral drugs/foods are tolerated

Pediatric Dosing

Acute hyperammonemia

• 20 kg: 2.5 mL/kg IV over 90-120 mins, followed by maintenance dose of 2.5 mL/kg over 24 hrs
• Provides 250 mg/kg sodium phenylacetate/250 mg/kg sodium benzoate
• >20 kg: 55 mL/m² IV over 90-120 mins, followed by maintenance dose of 55 mL/m² over 24 hrs
• Provides 5.5 g/m² sodium phenylacetate/5.5 g/m² sodium benzoate

• Consider co-administration of arginine in hyperammonemic infants. Therapy may be stopped when hyperammonemia is resolved and oral drugs/foods are tolerated

[Outline]

• Adult Dosing
• Pediatric Dosing

• Adjunctive therapy for acute hyperammonemia and associated encephalopathy in patients with deficiencies in enzymes of the urea cycle

• Hypersensitivity to any of the ingredients of the product
• Peripheral line administration

• N/A

Renal Dose Adjustment

• Renal impairment: Dose adjustments not defined; caution advised

Hepatic Dose Adjustment

• Hepatic impairment: Dose adjustments not defined; caution advised

• Acute symptomatic hyperammonemia may occur and may require hemodialysis to remove ammonia. Uncontrolled hyperammonemia may lead to brain damage or death. Manage hyperammonemia due to inborn errors of metabolism in coordination with medical personnel familiar with these diseases. Monitor plasma ammonia levels, neurological status, laboratory tests, clinical response, plasma K+ levels and serum electrolyte levels
• Use cautiously in patients with congestive heart failure or severe renal insufficiency and in conditions in which there is sodium retention with edema. Discontinue the treatment if adverse events occur and institute appropriate therapeutic measures
• Therapy should be administered through central line; administration through peripheral line may cause burns. Skin necrosis has been reported due to extravasation into perivenous tissues; if suspected, discontinue and resume at a different infusion site if necessary. Closely monitor infusion site for possible infiltration during administration and do not administer undiluted product
• Neurotoxicity has been reported in cancer patients receiving IV phenylacetate
• Therapy may cause adverse effects associated with salicylate overdose such as hyperventilation and metabolic acidosis; perform blood chemistry profiles, frequent blood pH and pCO2 monitoring

Cautions: Use cautiously in

• Hepatic impairment
• Renal impairment
• Sodium retention with edema
• Systemic steroid use

Pregnancy Category:C

Breastfeeding: Safety unknown. Manufacturer advises caution

• CV: Hypotension
• NEURO: Brain edema, coma, convulsions, cerebral edema, seizures, encephalopathy, neurotoxicity
• PSYCHIATRY: Mental impairment, agitation
• GI: Diarrhea, nausea, vomiting, GI hemorrhage
• GU: Urinary tract infection
• HEMA: Anemia, disseminated intravascular coagulation
• METABOLIC: Metabolic acidosis, hyperammonemia, hyperglycemia, hypocalcemia, hypokalemia
• DERM: Vascular disorders
• EENT: Blindness
• RESP: Respiratory distress, hyperventilation
• HEPA: Hepatotoxicity
• MISC: Pyrexia, sepsis
• LOCAL: Injection-site reaction

• Antihyperammonemic; alternative pathway for nitrogen disposal in patients without a fully functioning urea cycle
• Metabolized in liver; CYP450: unknown
• Excreted in urine
• Half-life: Unknown

US Trade Name(s)

• Ammonul

US Availability

Ammonul (sodium benzoate/sodium phenylacetate)

• INJ: 10%/10%

Canadian Trade Name(s)

• N/A

Canadian Availability

• N/A

UK Trade Name(s)

• N/A

UK Availability

• N/A

Australian Trade Name(s)

• N/A

Australian Availability

• N/A

[Outline]

Endocrine/Metabolic

Others