PHEBURANE Sodium phenylbutyrate Kit
🆔 Identity & classification
Where does this data come from?
🏷️ RxNorm drug class
This medicine belongs to the Nitrogen Binding Agent class.
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🏭 Manufacturer & labeler
Where does this data come from?
🩺 Clinical
Patient education
Supplement & herbal interactions
Some supplements/herbs that may interact with Sodium Phenylbutyrate — tap one for details:
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Ask a licensed pharmacist directly — free, answered by our team.
🧪 Inactive Ingredients / Excipients
Inactive ingredients, also called excipients, are components of the drug product other than the active ingredient. They may include fillers, dyes, coatings, preservatives, flavors, or other formulation ingredients.
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IACT rows and label-wide narrative are kept separate; availability and product-level specificity depend on the submitted label.Inactive ingredient FAQ
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💲 Pricing
A drug doesn't have one price. Each row is a different public payment system, and none is what you'd pay at the counter — that depends on your insurance. The ⓘ on each row explains what it measures.
| Price system | Per each | Per package |
|---|---|---|
| Retail pharmacies payNADAC · weekly | Not in the retail survey — common for institutional, discontinued, or low-volume packs. | |
| Medicaid paysCMS SDUD · 12 mo | No recent Medicaid claims on file for this NDC — rare and low-volume NDCs are suppressed in the public data. | |
| Medicare drug plans payPart D · Q2 2026 | $25.14 | — |
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🔁 Therapeutic equivalents
| Product | Labeler | Pack | NADAC/unit | TE | Status | Price vs. this |
|---|---|---|---|---|---|---|
| Pheburanethis 71770-0200-10 | Medunik | 1 kit | — | — | FDA listed | — |
| Pheburane 483 mg/g 71770-0210-10 | Medunik | 174 g | — | — | FDA listed | — |
| Olpruva 72542-0300-09 | Acer | 1 kit | — | — | FDA listed | — |
| sodium phenylbutyrate 423 mg/g 49629-0043-01 | Rottendorf | 72 bottles | — | — | FDA listed | — |
| Olpruva 72542-0600-18 | Acer | 1 kit | — | — | FDA listed | — |
| Olpruva 72542-0400-18 | Acer | 1 kit | — | — | FDA listed | — |
| Olpruva 72542-0500-18 | Acer | 1 kit | — | — | FDA listed | — |
| Olpruva 72542-0200-09 | Acer | 1 kit | — | — | FDA listed | — |
| Olpruva 72542-0667-18 | Acer | 1 kit | — | — | FDA listed | — |
Where does this data come from?
⏳ Availability & generic status
We did not find an FDA-approved generic match for this exact strength, form and route.
Where does this data come from?
📊 Medicare Part D spend CMS · PART D · 2025 (Q1-Q4)
🔬 Reported adverse events (FAERS)
Top reported reactions
Age at onset
Reporter sex
Serious outcomes
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📦 Packaging — all sizes for this product
| Package NDC | Description | Marketing start | Status |
|---|---|---|---|
| 71770-0200-10 You're viewing this | 1 KIT in 1 CARTON (71770-200-10) * 174 g in 1 BOTTLE (71770-210-10) | 2022-08-26 | Active |
🧭 About this NDC listing & data coverage
Kit / multi-component package
This NDC identifies a kit — a package containing more than one component. Structured data (pricing, ingredients, equivalents) is often reported per component rather than for the kit NDC itself, which can make this page look thinner than the components' own pages.
What data is (and isn’t) available for this NDC — tap to expand
| NDC identity (package / product / labeler codes) | ✓ Available |
| Labeler | ✓ Available |
| Product & package description | ✓ Available |
| Marketing category & status | ✓ Available |
| Active ingredient / dosage form / route | ✓ Available |
| FDA label (SPL via DailyMed) | ✓ Available |
| Package photos | ✓ Available |
| Inactive ingredients (structured) | — Not published for this NDC The labeler did not submit a structured excipient list, or no SPL is available. |
| NADAC pharmacy acquisition price (CMS) | — Not published for this NDC CMS publishes NADAC only for NDCs reported in its retail-pharmacy survey. |
| Orange Book / therapeutic-equivalence data | — Not published for this NDC Applies only to products approved under an NDA/ANDA; many listings are out of scope. |
| HCPCS J-code billing crosswalk | — Not published for this NDC Most self-administered / retail products have no J-code — that is normal. |
| Medicaid utilization (CMS SDUD) | — Not published for this NDC CMS reports utilization only for NDCs with Medicaid claims above its privacy threshold. |
Questions about this listing
Why is there no price listed?
Is the NDC printed on the package the same as the 11-digit billing NDC?
What do the three segments of this NDC mean?
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Do I need a prescription for this product?
Where does this data come from?
📄 Full prescribing information FDA SPL
🎯 Indications and Usage ▾
1 INDICATIONS AND USAGE PHEBURANE is indicated as adjunctive therapy to standard of care, which includes dietary management, for the chronic management of adult and pediatric patients with urea cycle disorders (UCDs), involving deficiencies of carbamylphosphate synthetase (CPS), ornithine transcarbamylase (OTC) or argininosuccinic acid synthetase (AS). Limitations of Use Episodes of acute hyperammonemia may occur in patients while on PHEBURANE. PHEBURANE is not indicated for the treatment of acute hyperammonemia, which can be a life-threatening medical emergency that requires rapid acting interventions to reduce plasma ammonia levels.
PHEBURANE is a nitrogen-binding agent indicated as adjunctive therapy to standard of care, which includes dietary management, for the chronic management of adult and pediatric patients with urea cycle disorders (UCDs), involving deficiencies of carbamylphosphate synthetase (CPS), ornithine transcarbamylase (OTC) or argininosuccinic acid synthetase (AS). ( 1 ) Limitations of Use PHEBURANE is not indicated for the treatment of acute hyperammonemia. ( 1 )
⏱️ Dosage and Administration ▾
2 DOSAGE AND ADMINISTRATION PHEBURANE treatment should be supervised by a healthcare provider experienced in the treatment of UCDs. For administration, see full prescribing information. ( 2.1 , 2.4 ) The recommended dosage measured as sodium phenylbutyrate is: Patients weighing < 20 kg: 450–600 mg/kg/day of sodium phenylbutyrate orally.
( 2.1 ) Patients weighing ≥ 20 kg: 9.9–13.0 g/m 2 /day of sodium phenylbutyrate orally. ( 2.1 ) Monitor plasma ammonia levels to determine the need for dosage adjustment. ( 2.2 ) Monitor patients for potential neurotoxicity.
( 2.2 ) For patients with hepatic impairment, start at the lower end of the recommended dosing range. ( 2.3 )
2.1Recommended Dosage PHEBURANE treatment should be supervised by a healthcare provider experienced in the treatment of urea cycle disorders. The recommended dosage of PHEBURANE (measured as sodium phenylbutyrate) for patients with urea cycle disorders is: Patients weighing less than 20kg: 450 – 600 mg/kg/day of sodium phenylbutyrate orally. Divide the calculated total daily dose into three to six doses.
Administer as three to six divided doses and take with food. Patients weighing greater than or equal to 20 kg: 9.9 – 13 g/m 2 /day of sodium phenylbutyrate orally. Divide the calculated total daily dose into three to six doses.
Administer as three to six divided doses and take with food. The maximum dosage is 20 grams per day. Combine PHEBURANE with dietary protein restriction and, in some cases, amino acid supplementation (e.g., essential amino acids, arginine, citrulline, and protein-free calorie supplements).
Measure the dose using only the calibrated spoon provided in the packaging. This calibrated dosing spoon directly measures PHEBURANE oral pellets as sodium phenylbutyrate [see Dosage and Administration ( 2.4 ) ] . Missed Dose If a dose is missed, take the missed dose as soon as possible.
There should be at least 3 hours between two doses and doses should not be doubled to make up for the missed dose.
2.2Dosage Adjustment and Monitoring Monitor plasma ammonia levels to determine the need for dosage adjustment. Adjust the PHEBURANE dosage to maintain the plasma ammonia level within the normal range for the patient’s age, taking into consideration their clinical condition (e.g., nutritional requirements, protein intake, growth parameters, etc.). Monitor patients for potential neurotoxicity and obtain measurements of plasma phenylacetate and phenylacetylglutamine levels [see Warnings and Precautions ( 5.1 ), Adverse Reactions ( 6 )] .
If neurologic symptoms (e.g. vomiting, nausea, headache, somnolence or confusion) are present in the absence of high ammonia levels or other intercurrent illnesses, consider reducing the dose of PHEBURANE.
2.3Dosage Adjustment in Patients with Hepatic Impairment For patients with hepatic impairment, start at the lower end of the recommended dosing range and maintain patients on the lowest dose necessary to control plasma ammonia levels [see Use in Specific Populations ( 8.7 )] .
2.4Administration Instructions For oral administration only. Administration via gastrostomy or nasogastric tubes has not been evaluated. Schedule PHEBURANE dosages at the same time as food consumption (meal or snack).
Use the calibrated dosing spoon to measure PHEBURANE oral pellets. The dosing spoon is directly calibrated in grams of sodium phenylbutyrate. Swallow the coated oral pellets with a drink (e.g., water, fruit juices, protein-free infant formulas) or sprinkle onto spoonful of apple sauce or carrot puree.
Do not chew PHEBURANE oral pellets directly or mix into liquids. Swallow immediately to minimize dissolution of coating. Administration of PHEBURANE oral pellets with other foods has not been studied and is not recommended.
Additionally, administration with soft food is only recommended in patients old enough to consume soft foods.
💊 Dosage Forms and Strengths ▾
3 DOSAGE FORMS AND STRENGTHS Oral pellets: 84 g of sodium phenylbutyrate per PHEBURANE bottle as white to off-white coated pellets. Oral pellets: 84 g of sodium phenylbutyrate per bottle. ( 3 )
⛔ Contraindications ▾
4 CONTRAINDICATIONS None None. ( 4 )
⚠️ Warnings and Cautions ▾
5 WARNINGS AND PRECAUTIONS Neurotoxicity of Phenylacetate : Increased exposure to phenylacetate, the major metabolite of PHEBURANE, may be associated with neurotoxicity in patients with UCDs. Consider reducing the dose if neurotoxicity symptoms are present. ( 5.1 ) Hypokalemia : Renal excretion of phenylacetylglutamine may induce urinary loss of potassium.
Monitor serum potassium during therapy and initiate appropriate treatment when necessary. ( 5.2 ) Conditions Associated with Edema : Calculate the total amount of sodium patients will be exposed to based on their weight or body surface area. If a patient develops new-onset edema or worsening edema while on treatment, discontinue administration of PHEBURANE and initiate appropriate therapy.
( 5.3 ) Diabetes Mellitus, Hereditary Fructose Intolerance, Glucose-Galactose Malabsorption or Sucrase-Isomaltase Insufficiency : Avoid use of PHEBURANE in patients with rare hereditary problems of fructose intolerance, glucose-galactose malabsorption or sucrase-isomaltase insufficiency. ( 5.4 )
5.1Neurotoxicity of Phenylacetate Increased exposure to phenylacetate, the major metabolite of PHEBURANE, may be associated with neurotoxicity in patients with UCDs. In a study of adult cancer patients receiving intravenous phenylacetate, 250-300 mg/kg/day for 14 days, repeated at 4-week intervals, signs and symptoms of neurotoxicity, which were reversible upon discontinuation, were seen at plasma concentrations ≥ 3.5 mmol/L, and included somnolence, fatigue, and light headedness [see Adverse Reactions ( 6 ) ] . PHEBURANE is not approved for intravenous use or for treatment of patients with cancer.
If symptoms of vomiting, nausea, headache, somnolence or confusion are present in the absence of high ammonia levels or other intercurrent illnesses, consider reducing the dose of PHEBURANE [see Dosage and Administration ( 2.2 )] . Phenylacetate caused neurotoxicity when given subcutaneously in rat pups [see Use in Specific Populations ( 8.4 )] .
5.2Hypokalemia Renal excretion of phenylacetylglutamine may induce urinary loss of potassium. Monitor serum potassium during therapy and initiate appropriate treatment when necessary.
5.3Conditions Associated with Edema PHEBURANE contains 124 mg (5.4 mmol) of sodium per gram of sodium phenylbutyrate, corresponding to 2.5 g (108 mmol) of sodium in the maximum daily dose of 20 g of sodium phenylbutyrate. In order to decide if administration of PHEBURANE is appropriate in patients with diseases that involve edema such as heart failure, cirrhosis, or nephrosis, calculate the total amount of sodium patients will be exposed to based on their weight or body surface area (BSA) [see Dosage and Administration ( 2.1 )] .
If a patient develops new-onset edema or worsening edema while on treatment, discontinue administration of PHEBURANE and initiate appropriate therapy.
5.4Diabetes Mellitus, Hereditary Fructose Intolerance, Glucose-Galactose Malabsorption or Sucrase-Isomaltase Insufficiency PHEBURANE contains 768 mg of sucrose per gram of sodium phenylbutyrate, corresponding to 15.4 g of sucrose in the maximum daily dose of 20 g of sodium phenylbutyrate. This should be considered in patients with diabetes mellitus. Avoid use of PHEBURANE in patients with rare hereditary problems of fructose intolerance, glucose-galactose malabsorption or sucrase-isomaltase insufficiency.
🤒 Adverse Reactions ▾
6 ADVERSE REACTIONS The following adverse reactions associated with the use of sodium phenylbutyrate were identified in clinical studies or postmarketing reports. Because some of these reactions were reported voluntarily and from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Most common adverse reactions (incidence ≥ 3%) are amenorrhea or menstrual dysfunction (irregular menstrual cycles), decreased appetite, body odor and bad taste or taste aversion.
Less Common Clinical Adverse Reactions Blood and lymphatic system disorders: aplastic anemia, ecchymoses Cardiac disorders : arrhythmia Gastrointestinal disorders : abdominal pain, decreased appetite, gastritis, nausea and vomiting, constipation, rectal bleeding, peptic ulcer disease, pancreatitis Metabolism and nutrition disorders: increased weight, edema Nervous system disorders : syncope, headache Psychiatric disorders : depression Renal and urinary disorders : renal tubular acidosis Skin and subcutaneous tissue disorders : rash Laboratory Adverse Reactions Blood and lymphatic system disorders : anemia, leukopenia and leukocytosis, thrombocytopenia, thrombocytosis Hepatobiliary disorders: hyperbilirubinemia, increased blood alkaline phosphatase, increased transaminases Metabolism and nutrition disorders: acidosis, alkalosis, hyperchloraemia, hypophosphataemia, hyperuricemia, hyperphosphatemia, hypernatremia, hypokalemia, hypoalbuminemia, decreased total protein Clinical Adverse Reactions with Use of Phenylacetate Nervous system disorders: Neurotoxicity was reported in cancer patients receiving intravenous phenylacetate, the major metabolite of PHEBURANE (PHEBURANE is not approved for intravenous use or for treatment of patients with cancer).
Signs and symptoms were predominately somnolence, fatigue, and dizziness (lightheadedness); less frequently reported were headache, dysgeusia, hypoacusis, disorientation, memory impairment, and exacerbation of a pre-existing neuropathy. Most common adverse reactions (incidence ≥ 3%) are menstrual dysfunction, decreased appetite, body odor and bad taste or taste aversion. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Medunik USA, Inc. at 1-844-884-5520 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .
🔄 Drug Interactions ▾
7 DRUG INTERACTIONS Valproic Acid, Haloperidol, or Corticosteroids : May increase plasma ammonia level; monitor ammonia levels closely. ( 7.1 ) Probenecid : May inhibit renal excretion of metabolites of PHEBURANE including phenylacetate and phenylacetylglutamine; monitor for potential neurotoxicity. ( 7.2 )
7.1Potential for Other Drugs to Affect Ammonia Corticosteroids Use of corticosteroids may cause the breakdown of body protein and increase plasma ammonia levels. Valproic Acid and Haloperidol Hyperammonemia may be induced by haloperidol and by valproic acid. Monitor plasma ammonia levels closely when PHEBURANE is used concomitantly with corticosteroids, valproic acid, or haloperidol.
7.2Effects of Other Drugs on PHEBURANE Probenecid Probenecid may inhibit renal excretion of the metabolites of PHEBURANE including phenylacetate and phenylacetylglutamine. Monitor patients for potential neurotoxicity and measure plasma phenylacetate and phenylacetylglutamine levels when probenecid is used concomitantly with PHEBURANE [see Dosage and Administration ( 2.2 )] .
👥 Use in Specific Populations ▾
8 USE IN SPECIFIC POPULATIONS
8.1Pregnancy Risk Summary Available data with sodium phenylbutyrate use 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 with sodium phenylbutyrate. Based on published animal data, phenylacetate may be neurotoxic to the developing brain (see Data ) .
There are serious risks to the mother and fetus associated with untreated urea cycle disorders during pregnancy which can result in serious morbidity and mortality to the mother and fetus (see Clinical Considerations ) . The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss or other adverse outcomes.
In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Clinical Considerations Disease-Associated Maternal and/or Embryo/Fetal Risk Pregnancy is a time of increased metabolic demand which increases the risk for hyperammonemic episodes when metabolic demands are not met. Hyperammonemic episodes in pregnancy are associated with impaired cognition in the mother and an increased risk of maternal and fetal death.
Data In rats, intrauterine exposure to phenylacetate produced lesions in the neonatal brain in layer 5 of the cortical pyramidal cells; dendritic spines were longer and thinner than normal and reduced in number.
8.2Lactation Risk Summary There are no data on the presence of sodium phenylbutyrate and its metabolite in either human or animal milk, the effects on the breastfed infant, or the effects on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for PHEBURANE and any potential adverse effects on the breastfed infant from PHEBURANE or from the underlying maternal condition.
8.4Pediatric Use The safety and effectiveness of PHEBURANE have been established as adjunctive therapy to the standard of care, which includes dietary management, in the chronic management of pediatric patients with urea cycle disorders (UCDs), involving deficiencies of carbamylphosphate synthetase (CPS), ornithine transcarbamylase (OTC) or argininosuccinic acid synthetase (AS). PHEBURANE is not indicated for the treatment of acute hyperammonemia, which can be a life-threatening medical emergency that requires rapid acting interventions to reduce plasma ammonia levels.
The sodium content of PHEBURANE has the potential to cause new-onset edema or worsening edema from salt and water retention, particularly in patients with underlying predisposing conditions [see Warnings and Precautions ( 5.3 )] . Neurotoxicity has been observed in juvenile animals with phenylacetate exposure [see Warnings and Precautions ( 5.1 )] . Juvenile Animal Toxicity Data When given subcutaneously to rat pups, 190–474 mg/kg phenylacetate caused decreased proliferation and increased loss of neurons, and it reduced CNS myelin.
Cerebral synapse maturation was retarded, and the number of functioning nerve terminals in the cerebrum was reduced, which resulted in impaired brain growth.
8.5Geriatric Use Clinical studies of PHEBURANE did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function and of concomitant disease or other drug therapy.
8.6Renal Impairment No studies with PHEBURANE were conducted in subjects with renal impairment. Monitor plasma ammonia…
🤰 Pregnancy ▾
8.1Pregnancy Risk Summary Available data with sodium phenylbutyrate use 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 with sodium phenylbutyrate. Based on published animal data, phenylacetate may be neurotoxic to the developing brain (see Data ) .
There are serious risks to the mother and fetus associated with untreated urea cycle disorders during pregnancy which can result in serious morbidity and mortality to the mother and fetus (see Clinical Considerations ) . The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss or other adverse outcomes.
In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Clinical Considerations Disease-Associated Maternal and/or Embryo/Fetal Risk Pregnancy is a time of increased metabolic demand which increases the risk for hyperammonemic episodes when metabolic demands are not met. Hyperammonemic episodes in pregnancy are associated with impaired cognition in the mother and an increased risk of maternal and fetal death.
Data In rats, intrauterine exposure to phenylacetate produced lesions in the neonatal brain in layer 5 of the cortical pyramidal cells; dendritic spines were longer and thinner than normal and reduced in number.
🧒 Pediatric Use ▾
8.4Pediatric Use The safety and effectiveness of PHEBURANE have been established as adjunctive therapy to the standard of care, which includes dietary management, in the chronic management of pediatric patients with urea cycle disorders (UCDs), involving deficiencies of carbamylphosphate synthetase (CPS), ornithine transcarbamylase (OTC) or argininosuccinic acid synthetase (AS). PHEBURANE is not indicated for the treatment of acute hyperammonemia, which can be a life-threatening medical emergency that requires rapid acting interventions to reduce plasma ammonia levels.
The sodium content of PHEBURANE has the potential to cause new-onset edema or worsening edema from salt and water retention, particularly in patients with underlying predisposing conditions [see Warnings and Precautions ( 5.3 )] . Neurotoxicity has been observed in juvenile animals with phenylacetate exposure [see Warnings and Precautions ( 5.1 )] . Juvenile Animal Toxicity Data When given subcutaneously to rat pups, 190–474 mg/kg phenylacetate caused decreased proliferation and increased loss of neurons, and it reduced CNS myelin.
Cerebral synapse maturation was retarded, and the number of functioning nerve terminals in the cerebrum was reduced, which resulted in impaired brain growth.
🧓 Geriatric Use ▾
8.5Geriatric Use Clinical studies of PHEBURANE did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function and of concomitant disease or other drug therapy.
🆘 Overdosage ▾
10 OVERDOSAGE Overdoses of PHEBURANE exceeding ten-fold the maximum recommended dosage may produce emesis, CNS depression, metabolic acidosis with or without respiratory alkalosis, hypernatremia, hypokalemia, and hypophosphatemia. Symptoms of overdose overlap with those of acute hyperammonemia. If overdose occurs, discontinue PHEBURANE, monitor plasma phenylacetate and ammonia levels closely, and institute appropriate emergency management, which may include hemodialysis, continuous veno-venous hemofiltration (CVVH) or extracorporeal membrane oxygenation (ECMO).
🧬 Clinical Pharmacology ▾
12 CLINICAL PHARMACOLOGY
12.1Mechanism of Action Sodium phenylbutyrate is a pro-drug and is metabolized to phenylacetate. Phenylacetate is a metabolically-active compound that conjugates with glutamine via acetylation to form phenylacetylglutamine. Phenylacetylglutamine is excreted by the kidneys, hence providing an alternate vehicle for waste nitrogen excretion.
12.2Pharmacodynamics In patients with urea cycle disorders, sodium phenylbutyrate decreased elevated plasma ammonia and glutamine levels.
12.3Pharmacokinetics The pharmacokinetics of phenylbutyrate and its metabolite phenylacetate were characterized in healthy adult subjects following a single oral administration of PHEBURANE (3 g of sodium phenylbutyrate) under fasted and fed conditions. Absorption Under fasted condition, the mean (SD) maximum plasma concentration (Cmax) of phenylbutyrate ranged from 146 (30) to 169 (33) μg/mL, which was achieved at approximately 0.6 hour after PHEBURANE administration. The mean (SD) area under the plasma concentration-time curve (AUC) of phenylbutyrate ranged from 272 (78) to 283 (68) h*μg/mL.
Effect of Food Compared to fasted condition, AUC of phenylbutyrate decreased by 40-45% and C max of phenylbutyrate decreased by 55%, when PHEBURANE was administered with a high-fat, high-calorie meal (total 800 to 1000 calories with approximately 150, 250, and 500-600 calories from protein, carbohydrate, and fat, respectively). When PHEBURANE was administered with a normal-fat, normal-calorie, low-protein meal (total 600 to 700 calories with approximately 60, 200, and 400 calories from protein, fat, and carbohydrate, respectively), AUC of phenylbutyrate decreased by 56-63% and C max decreased by 43-45% compared to fasted condition.
Elimination The mean half-life of phenylbutyrate ranged from 0.5 to 0.8 hour. Metabolism Following oral administration, sodium phenylbutyrate is metabolized by β-oxidation into phenylacetate, which is converted to its coenzyme A ester, phenylacetyl-coenzyme A and further conjugated with glutamine to form phenylacetylglutamine. Phenylacetylglutamine is excreted by the kidneys.
The major sites for metabolism of sodium phenylbutyrate are the liver and kidneys. Phenylacetate is also hydrolysed by esterases in liver and blood. Excretion Approximately 80–100% of sodium phenylbutyrate is excreted by the kidneys within 24 hours as phenylacetylglutamine.
For each gram of sodium phenylbutyrate administered, it is estimated that between 0.12–0.15 grams of phenylacetylglutamine nitrogen are produced. Specific Populations Patients with Renal Impairment or Hepatic Impairment PHEBURANE has not been studied in patients with renal impairment or in patients with hepatic impairment. Drug Interaction Studies In Vitro Studies Sodium phenylbutyrate or phenylacetate is not an inhibitor of CYP2C8, CYP2C19 and CYP3A at clinically relevant concentrations.
Sodium phenylbutyrate or phenylacetate is not a substrate of efflux transporters P-gp and BCRP.
🧬 Mechanism of Action ▾
12.1Mechanism of Action Sodium phenylbutyrate is a pro-drug and is metabolized to phenylacetate. Phenylacetate is a metabolically-active compound that conjugates with glutamine via acetylation to form phenylacetylglutamine. Phenylacetylglutamine is excreted by the kidneys, hence providing an alternate vehicle for waste nitrogen excretion.
📦 How Supplied / Storage and Handling ▾
16 HOW SUPPLIED/STORAGE AND HANDLING PHEBURANE (sodium phenylbutyrate) oral pellets consists of white to off-white pellets and is available in a child-resistant high-density polyethylene (HDPE) bottle with a desiccant in the cap. Each bottle contains 84 g of sodium phenylbutyrate (equivalent to 74 g of phenylbutyrate) in 174 g of oral pellets (NDC 71770-200-10). Each gram of pellets contains 483 mg of sodium phenylbutyrate (equivalent to 423 mg of phenylbutyrate).
A calibrated measuring spoon that dispenses up to 3 g of sodium phenylbutyrate in increments of 0.25 g is provided in the packaging. Store PHEBURANE at 20°C to 25°C (68°F to 77°F); excursions permitted between 15°C and 30°C (59°F and 86°F) [see USP Controlled Room Temperature]. Discard any remaining PHEBURANE 45 days after first opening of the bottle.
📋 Description ▾
11 DESCRIPTION PHEBURANE (sodium phenylbutyrate) oral pellets is a nitrogen binding agent. Sodium phenylbutyrate is a white or yellowish-white powder, freely soluble in water and in methanol, and practically insoluble in methylene chloride. It is known chemically as sodium 4-phenylbutanoate with a molecular weight of 186.19 and the molecular formula C 10 H 11 NaO 2 .
Structural formula: Each bottle of PHEBURANE contains 84 g of sodium phenylbutyrate (equivalent to 74 g of phenylbutyrate) in 174 g of oral pellets. Each gram of pellets contains 483 mg of sodium phenylbutyrate (equivalent to 423 mg of phenylbutyrate). PHEBURANE contains the following inactive ingredients: ethylcellulose, hypromellose, polyethylene glycol 1500, povidone K25, and sugar spheres.
Structural formula
💬 Information for Patients ▾
17 PATIENT COUNSELING INFORMATION Advise the patient to read the FDA-approved patient labeling ( Patient Information and Instructions for Use ). Neurotoxicity Advise the patient or caregiver that neurotoxicity may occur during PHEBURANE treatment. Inform the patient or caregiver of the signs and symptoms of this risk and to contact the healthcare provider immediately if signs and symptoms occur [see Warnings and Precautions ( 5.1 )] .
Administration Instruct the patient or caregiver to only use the calibrated dosing spoon supplied with PHEBURANE to measure the oral pellets. Inform the patient or caregiver that the dosing spoon is directly calibrated in grams of sodium phenylbutyrate. Inform the patient or caregiver to consume the pellets immediately after preparation [see Dosage and Administration ( 2.4 )] .
Inform the patient or caregiver that if a dose is missed, take the missed dose as soon as possible. Instruct the patient or caregiver that there should be at least 3 hours between two doses and doses should not be doubled to make up for the missed dose [see Dosage and Administration ( 2.1 )] . Storage and Handling Advise the patient or caregiver to discard any remaining PHEBURANE 45 days after first opening of the bottle.
Distributed by: Medunik USA, Inc. 2 Research Way, Suite 1B Princeton, NJ 08540 PHEBURANE ® is a registered trademark of Lucane Pharma Medunik logo