Dosing & Uses
Dosage Forms & 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
Dosage Forms & 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
Interactions
Interaction Checker
No Results

Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor

Contraindicated (0)
Serious - Use Alternative (1)
- valproic acid
valproic acid decreases effects of sodium phenylacetate by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Valproic acid may exacerbate hyperammonemia in pts. with urea cycle disorders.
Monitor Closely (10)
- amoxicillin
amoxicillin, sodium phenylacetate. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.
- ampicillin
ampicillin, sodium phenylacetate. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.
- nafcillin
nafcillin, sodium phenylacetate. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.
- penicillin G aqueous
penicillin G aqueous, sodium phenylacetate. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.
- penicillin VK
penicillin VK, sodium phenylacetate. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.
- pivmecillinam
pivmecillinam, sodium phenylacetate. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.
- probenecid
probenecid increases levels of sodium phenylacetate by decreasing renal clearance. Use Caution/Monitor.
- temocillin
temocillin, sodium phenylacetate. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.
- ticarcillin
ticarcillin, sodium phenylacetate. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.
- tobramycin inhaled
tobramycin inhaled and sodium benzoate both increase nephrotoxicity and/or ototoxicity. Modify Therapy/Monitor Closely. Avoid concurrent or sequential use to decrease risk for ototoxicity
Minor (0)
Adverse 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 must be through central venous catheter; administration through peripheral line may cause burns; bolus infusion flow rates are relatively high, especially for infants; extravasation into perivenous tissues may lead to skin necrosis; if extravasation is suspected, discontinue infusion and resume at different infusion site, if necessary; monitor infusion site closely for possible infiltration during drug administration; do not administer undiluted product
Due to structural similarities between phenylacetate and benzoate to salicylate, drug may cause side effects typically associated with salicylate overdose, such as hyperventilation and metabolic acidosis; monitoring of blood chemistry profiles, blood pH and pCO2 should be performed
Because urine potassium loss is enhanced by excretion of non-reabsorbable anions, phenylacetylglutamine and hippurate, plasma potassium levels should be carefully monitored and appropriate treatment given when necessary
Should be used with great care, if at all, in patients with congestive heart failure or severe renal insufficiency, and in clinical states in which there is sodium retention with edema; discontinue administration, evaluate the patient, and institute appropriate therapeutic countermeasures if an adverse event occurs
Pregnancy & Lactation
Pregnancy
Available data in pregnant women are insufficient to identify a drug-associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes; animal reproduction studies have not been conducted
Lactation
There are no data on presence of sodium phenylacetate, sodium benzoate in either human or animal milk, effects on breastfed infant, or on milk production; developmental and health benefits of breastfeeding should be considered along with mother’s clinical need for therapy and any potential adverse effects on breastfed infant from drug or from underlying maternal condition
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
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
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Formulary
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