Dosing & Uses
Dosage Forms & Strengths
tablet (Buphenyl)
- 500mg
powder for oral suspension (Buphenyl)
- 3g/level teaspoon (measuring device included)
- 8.6g/level tablespoon (measuring device included)
oral pellets for suspension (Olpruva)
- 2g/packet
- 3g/packet
- 4g/packet
- 5g/packet
- 6g/packet
- 6.67g/packet
oral pellets (Pheburane)
- 84g/bottle
Urea Cycle Disorders
Indicated as an adjunct to dietary protein restriction and essential amino acid supplementation for the chronic management of patients with urea cycle disorders involving deficiencies of carbamylphosphate synthetase (CPS), ornithine transcarbamylase (OTC), or argininosuccinic acid synthetase (AS)
It is indicated in all patients with neonatal-onset deficiency (complete enzymatic deficiency, presenting within the first 28 days of life) and for late-onset disease (partial enzymatic deficiency, presenting after the first month of life) who have a history of hyperammonemic encephalopathy
Buphenyl tablets, Olpruva, Pheburane
Dosage Modifications
Hepatic impairment
- Start at lower end of recommended dosing range and maintain on lowest dose necessary to control plasma ammonia levels
Sickling Disorders (Orphan)
Orphan designated treatment of disorders including hemoglobinopathies S-S, S-C, and S-thalassemia
Orphan sponsor
- Medicis Pharmaceutical Corp; 8125 N. Hayden Rd; Scottsdale, AZ 85258
Malignant Glioma (Orphan)
Orphan designation for adjunct to surgery, radiation, & chemotherapy in the treatment of primary or recurrent malignant glioma
Orphan sponsor
- Elan Drug Delivery, Inc; 1300 Gould Dr; Gainesville, GA 30504
Spinal Muscular Atrophy (Orphan)
Orphan designation for treatment of spinal muscular atrophy
Orphan sponsors
- Ucyclyd Pharma, Inc; 7720 N. Dobson Rd; Scottsdale, AZ 85256
- Tikvah Therapeutics, Inc; 75 5th St, NW; Atlanta, GA 30308
- GMP-Orphan SAS; 7, rue du Pasteur Wagner, F-75011; Paris, France
Dosing Considerations
Must be combined with dietary protein restriction and, in some cases, essential amino acid supplementation
Monitor plasma amino acids, ammonia
Limitations of use
- Episodes of acute hyperammonemia may occur in patients while taking sodium phenylbutyrate
- Not indicated for treatment of acute hyperammonemia, which can be a life-threatening medical emergency that requires rapid acting interventions to reduce plasma ammonia levels
Dosage Forms & Strengths
tablet (Buphenyl)
- 500mg
powder for oral suspension (Buphenyl)
- 3g/level teaspoon (measuring device included)
- 8.6g/level tablespoon (measuring device included)
oral pellets for suspension (Olpruva)
- 2g/packet
- 3g/packet
- 4g/packet
- 5g/packet
- 6g/packet
- 6.67g/packet
oral pellets (Pheburane)
- 84g/bottle
Urea Cycle Disorders
Indicated as an adjunct to dietary protein restriction and essential amino acid supplementation for the chronic management of patients with urea cycle disorders involving deficiencies of carbamylphosphate synthetase (CPS), ornithine transcarbamylase (OTC), or argininosuccinic acid synthetase (AS)
It is indicated in all patients with neonatal-onset deficiency (complete enzymatic deficiency, presenting within the first 28 days of life) and for late-onset disease (partial enzymatic deficiency, presenting after the first month of life) who have a history of hyperammonemic encephalopathy
≥20 kg
- Buphenyl tablets, Olpruva, Pheburane
- 9.9-13 g/m²/day PO divided in 3-6 doses; not to exceed 20 g/day
<20 kg
- Buphenyl tablets, Buphenyl powder for suspension, Pheburane
- 450-600 mg/kg/day PO divided in 3-6 doses
Dosage Modifications
Hepatic impairment
- Start at lower end of recommended dosing range and maintain on lowest dose necessary to control plasma ammonia levels
Dosing Considerations
Must be combined with dietary protein restriction and, in some cases, essential amino acid supplementation
Monitor plasma amino acids, ammonia
Limitations of use
- Episodes of acute hyperammonemia may occur in patients while taking sodium phenylbutyrate
- Not indicated for treatment of acute hyperammonemia, which can be a life-threatening medical emergency that requires rapid acting interventions to reduce plasma ammonia levels
Interactions
Interaction Checker
No Results

Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor

Contraindicated (0)
Serious - Use Alternative (0)
Monitor Closely (1)
- probenecid
probenecid increases levels of sodium phenylbutyrate by decreasing renal clearance. Use Caution/Monitor.
Minor (0)
Adverse Effects
>10%
Amenorrhea/dysmenorrhea (23%)
Hypoalbuminemia (11%)
Metabolic acidosis (14%)
1-10%
Anemia (9%)
Anorexia (4%)
Hypophosphatemia (2%)
Hypernatremia (1%)
Hyperuricemia (2%)
Hypokalemia (1%)
Leukopenia (4%)
Strong body odor (3%)
Thrombocytopenia (3%)
Warnings
Contraindications
Hypersensitivity
Acute hyperammonemia
Cautions
Renal insufficiency, hepatic insufficicency, CHF
Patients on restricted sodium intake (contains 125 mg Na/g)
Powder should not be mixed with acidic liquids
May cause sodium and fluid retention; caution in patients that poorly tolerate fluid retention like those with heart failure
Hyperammonemia and hyperammonemic encephalopathy may occur while on therapy (manage hyperammonemia as a medical emergency
Will not reverse existing hyperammonemia-inflicted neurologic damage
Low protein diet recommended with possible amino acid substitution
Pregnancy & Lactation
Pregnancy Category: C
Lactation: 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
Mechanism of Action
Decreases elevated plasma ammonia glutamine levels
Prodrug that is rapidly metabolized to phenylacetate which conjugates with glutamine to form phenylacetylglutamine, a nitrogen waste product that is excreted renally
The phenylacetylglutamine conjugate provides an alternate vehicle to urea for waste nitrogen excretion; for each gram of sodium phenylbutyrate administered, it is estimated that between 0.12–0.15 grams of phenylacetylglutamine nitrogen are produced
Absorption
Peak plasma time: 1-1.35 hr (phenylbutyrate); 3.55-3.74 hr (phenylacetate)
Peak plasma concentration: 195-218 mcg/mL (phenylbutyrate); 45.3-48.5 mcg/mL (phenylacetate)
Metabolism
Sodium phenylbutyrate: Liver, and kidney
Elimination
Half-life: 0.8 hr (phenylbutyrate); 1.15-1.29 hr (phenylacetate)
Excretion: Urine 80-100% (as phenylacetylglutamine)
Administration
Oral Administration
Schedule dosages at the same time as food consumption (meal or snack)
Powder for suspension (Buphenyl)
- For oral use (via mouth, gastrostomy, or nasogastric tube) only
- Mix powder with food (solid or liquid) for immediate use; however, when dissolved in water, has been shown to be stable for up to 1 week at room temperature or refrigerated
- Sodium phenylbutyrate is very soluble in water (5g/10mL)
- When powder is added to a liquid, only sodium phenylbutyrate will dissolve, however, the excipients will not
- Effect of food on sodium phenylbutyrate has not been determined
- Each level teaspoon (enclosed) dispenses 3 g of sodium phenylbutyrate
- Each level tablespoon (enclosed) dispenses 8.6 g of sodium phenylbutyrate
- Shake lightly before use
Pellets
- For oral administration only
- Administration vial G-tubes or NG-tubes has not been evaluated
-
Olpruva
- Pour entire contents of Mix-Aid packet into ~4 ounces of water in a cup and stir, forming a suspension
- Pour entire contents of sodium phenylbutyrate packet(s) into suspension and stir
- Drink entire suspension within 5 minutes after stirring to minimize dissolution of coating; discard suspension after 30 minutes if not consumed
- Pour another 4 ounces of water into cup and drink to make sure that any sodium phenylbutyrate remaining in cup is consumed
-
Pheburane
- Use calibrated dosing spoon to measure oral pellets; dosing spoon is directly calibrated in grams of sodium phenylbutyrate
- Swallow coated oral pellets with a drink (eg, water, fruit juices, protein-free infant formulas) or sprinkle onto spoonful of apple sauce or carrot puree
- Do not chew oral pellets directly or mix into liquids
- Swallow immediately to minimize dissolution of coating
Missed dose
- If dose missed, take as soon as possible
- There should be at least 3 hr between doses
- Do not double dose to make up for missed dose
Images
BRAND | FORM. | UNIT PRICE | PILL IMAGE |
---|---|---|---|
sodium phenylbutyrate oral - | 0.94 gram/gram powder | ![]() | |
sodium phenylbutyrate oral - | 0.94 gram/gram powder | ![]() | |
Buphenyl oral - | 500 mg tablet | ![]() |
Copyright © 2010 First DataBank, Inc.
Patient Handout
sodium phenylbutyrate oral
SODIUM PHENYLBUTYRATE PELLETS - ORAL
(SOE-dee-um FEN-il-BUE-ti-rate)
COMMON BRAND NAME(S): Olpruva
USES: This medication is used along with diet changes for long-term treatment of a certain inherited disorder (urea cycle disorder). Sodium phenylbutyrate helps remove a certain chemical (ammonia) from the body. Too much ammonia in the body can cause brain damage and sometimes death.This medication should not be used to treat sudden, severely high levels of ammonia in the body. Get medical help right away if you have sudden symptoms of too much ammonia (such as trouble thinking, nausea, vomiting, irritability, trouble speaking, trouble walking, fainting).
HOW TO USE: Read the Patient Information Leaflet and Instructions for Use provided by your pharmacist before you start taking sodium phenylbutyrate and each time you get a refill. Follow the illustrated directions for the proper use of this medication. If you have any questions, ask your doctor or pharmacist.Take this medication by mouth exactly as directed by your doctor. The dosage is based on your weight or body size, medical condition, and response to treatment. The total daily dose should be divided into equal amounts and taken with each meal or feeding (such as 3 to 6 times daily). Do not increase or decrease your dose without your doctor's approval.This medication must be mixed as directed before taking. To prepare a dose, pour the contents of the thickening packet into a cup with 4 ounces/120 milliliters of water. Stir well for at least 30 seconds until the water thickens. Then, open the packet(s) containing sodium phenylbutyrate and pour its contents into the cup with the thickened water mixture. Stir well for 15 seconds and drink all of the mixture within 5 minutes of mixing. Add more water to the cup, stir, and drink all of the mixture to make sure you are getting the entire dose. Discard mixture after 30 minutes. Do not prepare a supply in advance. Do not give through a feeding tube.Use this medication regularly to get the most benefit from it. To help you remember, take it at the same times each day.
SIDE EFFECTS: Loss of appetite or menstrual changes (delayed/irregular/absent periods) may occur. If either of these effects lasts or gets worse, tell your doctor or pharmacist promptly.Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.Tell your doctor right away if you have any serious side effects, including: drowsiness/lightheadedness, easy bruising/bleeding, fast/pounding heartbeat, mental/mood changes, tiredness, signs of metabolic imbalance (such as rapid breathing, muscle twitching/spasms).A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
PRECAUTIONS: Before taking sodium phenylbutyrate, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: a certain heart problem (heart failure), kidney disease, liver disease, swelling (edema).This medication contains salt (sodium). Before taking this medication, tell your doctor or pharmacist if you are on a low-salt diet.This drug may make you dizzy or drowsy. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.It is unknown if this medication passes into breast milk. Consult your doctor before breast-feeding.
DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.
OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.
NOTES: Do not share this medication with others.Lab and/or medical tests (such as plasma ammonia/amino acid levels, complete blood count, blood chemistries, urine tests, drug levels) should be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.
MISSED DOSE: If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.
STORAGE: Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
Information last revised June 2023. Copyright(c) 2023 First Databank, Inc.
IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.
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