Dosing and uses of Ammonul (sodium benzoate/sodium phenylacetate)
Adult dosage forms and strengths
sodium benzoate/sodium phenylacetate
injectable solution
- 10% / 10%
Urea Cycle Enzyme Deficiency
Indicated as adjunctive therapy for the treatment of acute hyperammonemia and associated encephalopathy in patients with deficiencies in enzymes of the urea cycle
Loading dose (>20 kg): 5.5 g-5.5 g/m² IV infusion over 90-120 minutes
Maintenance: 5.5 g-5.5 g/m² IV infusion over 24 hours
Encephalopathy (Orphan)
Treatment of grade III & IV hepatic encephalopathy
Orphan indication sponsor
- Ucyclyd Pharma, Inc; 7720 N. Dobson Rd; Scottsdale, AZ 85256
Monitor
Serum ammonia, neurological tests, clinical response, electrolytes
Pediatric dosage forms and strengths
sodium benzoate/sodium phenylacetate
injectable solution
- 10% / 10%
Urea Cycle Enzyme Deficiency
Indicated as adjunctive therapy for the treatment of acute hyperammonemia and associated encephalopathy in patients with deficiencies in enzymes of the urea cycle
Loading dose (<20 kg): 250 mg-250 mg/kg (2.5 mL/kg) IV infusion over 90-120 minutes
Maintenance: 250 mg-250 mg/kg (2.5 mL/kg) IV infusion over 24 hr
Monitor
Serum ammonia, neurological tests, clinical response, electrolytes
Ammonul (sodium benzoate/sodium phenylacetate) adverse (side) effects
>10%
Vomiting (12%)
1-10%
Acidosis (3%)
Agitation (3%)
Anemia (4%)
Brain edema (5%)
Coma (3%)
Convulsions (6%)
Diarrhea (3%)
DIC (3%)
Hyperammonemia (5%)
Hyperglycemia (7%)
Hypocalcemia (3%)
Hypotension (4%)
Inj-site reaction (3%)
Mental impairment (6%)
Nausea (3%)
Pyrexia (5%)
Respiratory distress (3%)
Skin disorder (6%)
UTI (3%)
Warnings
Contraindications
Hypersensitivity
Cautions
Discontinue oral antihyperammonemic drugs prior to administration
Caution in hepatic/renal impairment, heart failure, sodium retention associated with edema
Avoid repeat loading doses
Nausea/vomiting may occur
Contains 30.5 mg/mL of sodium in undiluted product
Phenylacetate has been associated with neurotoxicity risk
Administration through peripheral line may cause burns
Pregnancy and lactation
Pregnancy category: C
Lactation: Not known whether distributed in breast milk, use caution
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Ammonul (sodium benzoate/sodium phenylacetate)
Mechanism of action
Each component of the product provide an alternative pathway for removal of ammonia through the formation of their metabolites
Pharmacokinetics
Metabolism: Liver, kidney
Excretion: Urine
Administration
IV Preparation
Dilute with D10W
IV Administration
Administer through central line
Discontinue analogous oral drugs prior to administration
Load infusion over 90-120 min; maint over 24 hr
Extravasation Mgmt
If extravasation suspected, discontinue infusion & resume at different site, if necessary
Standard tx include aspiration of drug from catheter, limb elevation, intermittent cold packs
