Prior Authorization Criteria for Approval

Sodium phenylbutyrate will be approved when ALL of the following are met:

1. The patient has a diagnosis of ONE of the following:
   1. Urea cycle disorder with neonatal-onset involving deficiencies of carbamylphosphate synthetase, ornithine transcarbamylase, or argininosuccinic acid synthetase
      OR
   2. Urea cycle disorder with late-onset and history of hyperammonemic encephalopathy involving deficiencies of carbamylphosphate synthetase, ornithine transcarbamylase, or argininosuccinic acid synthetase
      AND
2. The prescriber is a specialist in the area of the patient’s diagnosis (e.g., geneticist, metabolic disorders) or the prescriber has consulted with a specialist in the area of the patient’s diagnosis
   AND
3. The patient does NOT have any FDA labeled contraindications to the requested medication
   AND
4. The requested dose is within FDA labeled dosing for the requested indication

Length of Approval: 12 months