Reye Syndrome Medication

Updated: Apr 02, 2015
  • Author: Debra L Weiner, MD, PhD; Chief Editor: Kirsten A Bechtel, MD  more...
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Medication Summary

No specific treatment is available for Reye syndrome. Supportive care to reduce hyperammonemia by giving sodium phenylacetate–sodium benzoate may be required. For highly elevated ammonia levels, hemodialysis may be the appropriate initial treatment if it is readily available, and it is also recommended for patients whose condition fails to respond to initial course of sodium phenylacetate–sodium benzoate. Continuing the administration of sodium phenylacetate–sodium benzoate during hemodialysis may be considered.

Corticosteroids are of no proven benefit with regard to managing increased intracranial pressure (ICP) and may even be harmful. Accordingly, they are not indicated in this setting.


Urea Cycle Disorder Treatment Agents

Class Summary

Ammonia detoxicants are used for treatment of hyperammonemia; they enhance elimination of nitrogen. Sodium phenylacetate–sodium benzoate is approved by the US Food and Drug Administration (FDA) for treatment of hyperammonemia due to urea-cycle defects and is available only from a specialty wholesaler, Ucyclyd Pharma, Inc (8125 N. Hayden Road, Scottsdale, AZ 85258; 24-hour toll-free number in the United States and Canada, 888-829-2593). For more information, see Ammonul prescribing information.

Sodium phenylacetate and sodium benzoate (Ammonul)

Sodium phenylacetate–sodium benzoate may be effective for treatment of hyperammonemia, though hemodialysis is preferred for ammonia levels higher than 500-600 µg/dL. It can be used until dialysis is started or along with dialysis.

Benzoate combines with glycine to form hippurate (which is excreted in urine); 1 mole of benzoate removes 1 mole of nitrogen. Phenylacetate conjugates (by acetylation) with glutamine in the liver and kidneys to form phenylacetylglutamine (which is excreted by the kidneys). The nitrogen content of phenylacetylglutamine per mole is identical to that of urea (2 mol).

The preparation contains 100 mg/mL each of sodium phenylacetate and sodium benzoate and is supplied as 50-mL vials. The intravenous (IV) dose must be diluted in at least 25 mL/kg of 10% dextrose, up to 600 mL. Sodium phenylacetate–sodium benzoate should not be directly mixed with other medications but may be piggybacked. It should be given in addition to the daily fluid requirement.


Antiemetic agents

Class Summary

Antiemetic agents such as ondansetron are administered to decrease vomiting and during the initiation of sodium phenylacetate–sodium benzoate therapy.

Ondansetron (Zofran, Zuplenz)

Ondansetron controls nausea and vomiting associated with Reye syndrome and with IV administration of sodium phenylacetate–sodium benzoate. It is a selective 5-HT3 receptor antagonist that blocks serotonin both peripherally and centrally.