sodium benzoate/sodium phenylacetate (Rx)

Brand and Other Names:Ammonul
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Dosing & Uses

AdultPediatric

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

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Interactions

Interaction Checker

and sodium benzoate/sodium phenylacetate

No Results

     activity indicator 
    No Interactions Found
    Interactions Found

    Contraindicated

      Serious - Use Alternative

        Significant - Monitor Closely

          Minor

            All Interactions Sort By:
             activity indicator 

            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)

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                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%)

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                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

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                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.

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                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

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                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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                Images

                No images available for this drug.
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                Patient Handout

                A Patient Handout is not currently available for this monograph.
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                Formulary

                FormularyPatient Discounts

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                The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.

                Tier Description
                1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
                2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
                3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
                4 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
                5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
                6 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
                NC NOT COVERED – Drugs that are not covered by the plan.
                Code Definition
                PA Prior Authorization
                Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
                QL Quantity Limits
                Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
                ST Step Therapy
                Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
                OR Other Restrictions
                Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each prescription.
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                Medscape prescription drug monographs are based on FDA-approved labeling information, unless otherwise noted, combined with additional data derived from primary medical literature.