Packed with possibility

Learn why OLPRUVA is the ammonia control solution for patients on the go.¹

OLPRUVA is a nitrogen-binding agent indicated as adjunctive therapy to the standard of care, which includes dietary management, in the chronic management of adult and pediatric patients 1 year of age and older weighing 7 kg or greater, 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 OLPRUVA. OLPRUVA is not indicated for the treatment of acute hyperammonemia, which can be a life-threatening medical emergency that requires rapidly acting interventions to reduce plasma ammonia levels.

OLPRUVA is not recommended for patients younger than 1 year of age due to the volume of free water required for daily administration.

OLPRUVA is designed to be portable, premeasured, and palatable to help fit into patients’ daily lives^1-3

OLPRUVA delivers the proven efficacy and safety of sodium phenylbutyrate in a novel formulation designed for patients on the go. Whether your patients are young adults transitioning to self-care or OTCD females, OLPRUVA is designed to be a palatable, premeasured sodium phenylbutyrate therapy, offering maximum convenience with no bitter flavor (when taken within 5 minutes) due to its dual coating.^1-3

PORTABLE:

Discreet single-dose envelopes are easily carried when your patients are on the go¹

PREMEASURED:

Convenient individual dose packets support dosing accuracy¹

PALATABLE:

Dual-coating* formulation is designed to mask the bitter taste of sodium phenylbutyrate^1-3

The active ingredient of OLPRUVA is covered by a seal coating and an outer polymer coating.

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Sodium phenylbutyrate has been a foundational therapy for certain UCDs for more than 25 years⁴

Sodium phenylbutyrate has a long history in UCD treatment^4,5 and was first approved by the FDA as a medication for certain UCDs in 1996⁵

OLPRUVA was approved by the FDA as a 505(b)(2) application, primarily based on^2,6:

Bioequivalence to sodium phenylbutyrate powder^1,2
FDA evaluation of the safety and effectiveness of sodium phenylbutyrate powder^5,6

Established safety profile of sodium phenylbutyrate powder based on >25 years of use in patients with UCDs^4,5

Most common adverse reactions (incidence ≥3%) are amenorrhea or menstrual dysfunction (irregular menstrual cycles), decreased appetite, body odor, and bad taste or taste aversion¹
<3% of patients experienced gastrointestinal effects¹

Like other nitrogen-binding agents that treat UCDs, OLPRUVA is metabolized to phenylacetate, the metabolically active compound that facilitates nitrogen excretion.¹

Phenylacetate conjugates with glutamine to form phenylacetylglutamine, which provides an alternate vehicle for waste nitrogen excretion¹
The OLPRUVA formulation is proprietary and patented

Bioequivalence: The proven efficacy of phenylbutyrate and phenylacetate

OLPRUVA was shown to be bioequivalent to sodium phenylbutyrate powder in two phase 1 pharmacokinetic studies⁷

Two phase 1 studies were conducted in healthy adult volunteers (N=37), using a single-dose (5 g of active ingredient, ie, sodium phenylbutyrate), 3-period, 3-sequence crossover design. Study drugs were given on days 1-3⁷:

In Study 1, subjects received OLPRUVA with a high-fat meal (fed), OLPRUVA fasted, and sodium phenylbutyrate powder fasted; OLPRUVA was prepared with modified Mix-Aid^†
In Study 2, subjects received OLPRUVA with Mix-Aid^† and sodium phenylbutyrate powder—all under fed conditions

Plasma concentrations of phenylbutyrate and the active metabolite phenylacetic acid (PAA) were determined using liquid chromatography-tandem mass spectrometry, and plasma samples were collected from all subjects prior to dosing and at multiple timepoints following study-drug administration.⁷

^†Mix-Aid (called Thick-It in the phase 1 studies) is 100% modified food starch used in commercially available OLPRUVA.

Teal and dark gray graph on a light gray background concerning mean plasma concentrations of phenylbutyrate under fed conditions.

Teal and dark gray graph on a light gray background concerning mean plasma concentrations of phenylacetate under fed conditions.

OLPRUVA is rapidly converted into the active metabolite phenylacetate, which allows for removal of ammonia.¹

Increased exposure to phenylacetate, the major metabolite of OLPRUVA, may be associated with neurotoxicity in patients with UCDs. OLPRUVA is not approved for intravenous use or for treatment of patients with cancer. If neurotoxicity 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 OLPRUVA.

Total systemic exposures (AUC_inf) and peak exposures (C_max) of phenylbutyrate and phenylacetate were bioequivalent for OLPRUVA and sodium phenylbutyrate powder in the fasted and fed states.^1,7

OLPRUVA should always be taken with food. Under fasted conditions, the C_max and AUC_inf were increased by 50% and 39%, respectively, for phenylbutyrate and 32% and 29%, respectively, for phenylacetate when compared to when OLPRUVA was administered with a high-fat meal.^‡

The maximum recommended daily dose for OLPRUVA is 20 grams.¹

^‡These data were derived from mean values for C_max and AUC_inf.

Teal and dark gray graph on a light gray background concerning Cmax and AUC of phenylbutyrate and phenylacetate following a single oral dose administration of OLPRUVA (5 g) in healthy subjects under fasted and fed conditions.

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Indication

OLPRUVA is a nitrogen-binding agent indicated as adjunctive therapy to the standard of care, which includes dietary management, in the chronic management of adult and pediatric patients 1 year of age and older weighing 7 kg or greater, 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 OLPRUVA. OLPRUVA is not indicated for the treatment of acute hyperammonemia, which can be a life-threatening medical emergency that requires rapidly acting interventions to reduce plasma ammonia levels.

OLPRUVA is not recommended for patients younger than 1 year of age due to the volume of free water required for daily administration.

Important Safety Information

Warnings and Precautions
Neurotoxicity of Phenylacetate: Increased exposure to phenylacetate, the major metabolite of OLPRUVA, may be associated with neurotoxicity in patients with UCDs. OLPRUVA is not approved for intravenous use or for treatment of patients with cancer. If neurotoxicity 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 OLPRUVA.

Hypokalemia: Renal excretion of phenylacetylglutamine may induce urinary loss of potassium. Monitor serum potassium during therapy and initiate appropriate treatment when necessary.

Conditions Associated with Edema: OLPRUVA contains 124 mg of sodium per gram of sodium phenylbutyrate, and the Mix-Aid contains 5 mg of sodium per packet. Calculate the total amount of sodium exposure based on the patient’s body surface area. If a patient develops new-onset edema or worsening edema while on treatment, discontinue administration of sodium phenylbutyrate and initiate appropriate therapy.

Drug Interactions

Valproic acid, haloperidol, or corticosteroids may increase plasma ammonia levels. Monitor ammonia levels closely. Probenecid may inhibit renal excretion of metabolites of OLPRUVA including phenylacetate and phenylacetylglutamine; monitor for potential neurotoxicity.

Use in Specific Populations

No studies with OLPRUVA have been conducted in subjects with renal or hepatic impairment. Monitor ammonia levels and in patients with hepatic impairment, it is recommended to start at the lowest dose that controls ammonia levels. Dose selection for elderly patients should be cautious, usually starting at the low end of the dosing range.

OLPRUVA should be used with caution in patients who are pregnant or planning to become pregnant. Report pregnancies to the manufacturer. There are no data on the presence of OLPRUVA in human milk, the effects on the breastfed infant, nor the effects on milk production. This should be considered when assessing the mother’s need for OLPRUVA.

Adverse Reactions

Most common adverse reactions (incidence ≥ 3%) are amenorrhea or menstrual dysfunction (irregular menstrual cycles), decreased appetite, body odor and bad taste or taste aversion.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch or call 1-800-FDA-1088.

This information is not comprehensive.

For additional information, please see full Prescribing Information.

References

OLPRUVA® (sodium phenylbutyrate) for oral suspension. Prescribing Information. Acer Therapeutics Inc.
Appel LE, Shockey JR, Schelling DC, inventors; Acer Therapeutics Inc, assignee. Palatable compositions including sodium phenylbutyrate and uses thereof. U.S. patent 11,154,521 (B2). October 26, 2021.
Keating AV, Soto J, Tuleu C, Forbes C, Zhao M, Craig DQM. Solid state characterisation and taste masking efficiency evaluation of polymer based extrudates of isoniazid for paediatric administration. Int J Pharm. 2018;536(2):536-546.
Osaka S, Nakano S, Mizuno T, et al. A randomized trial to examine the impact of food on pharmacokinetics of 4-phenylbutyrate and change in amino acid availability after a single oral administration of sodium 4-phenylbutyrate in healthy volunteers. Mol Genet Metab. 2021;132(4):220-226.
U.S. Department of Health and Human Services, Food and Drug Administration. Drugs@FDA: FDA-approved drugs, NDA 020572. Accessed May 1, 2025. https://www.accessdata.fda.gov/ scripts/cder/daf/index.cfm? event=overview.process &varApplNo=020572
U.S. Food and Drug Administration, Center for Drug Evaluation and Research (CDER). Determining Whether to Submit an ANDA or a 505(b)(2) Application: Guidance for Industry. May 2019.
Cederbaum SD, Edwards J, Kellmeyer T, Peters Y, Steiner RD. Taste-masked formulation of sodium phenylbutyrate (ACER-001) for the treatment of urea cycle disorders. Mol Genet Metab. 2023;138(4):107558.
Data on file. Acer Therapeutics Inc.

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OLPRUVA is a registered trademark of Acer Therapeutics Inc., a wholly owned subsidiary of Zevra Therapeutics, Inc. AMPLIFYASSIST is a trademark of Zevra Therapeutics, Inc. © 2025 Zevra Therapeutics, Inc. All rights reserved. PRC-OLP-25-033 12/25

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