Elevated ammonia is highly toxic, especially to the central nervous system (CNS)¹

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

• Stone WL, Basit H, Jaishankar GB. Urea cycle disorders. In StatPearls. StatPearls Publishing. Updated August 7, 2023. Accessed May 1, 2025. https://www.ncbi.nlm.nih.gov/ books/NBK482363/
• Donovan K, Vaqar S, Guzman N. Ornithine transcarbamylase deficiency. In StatPearls. StatPearls Publishing. Updated February 26, 2024. Accessed May 1, 2025. https://www.ncbi.nlm.nih.gov/ books/NBK537257/