PHEBURANE

The pharmacokinetics of phenylbutyrate and its metabolite phenylacetate were characterized in healthy adult subjects following a single oral administration of PHEBURANE (3 g of sodium phenylbutyrate) under fasted and fed conditions.

AbsorptionUnder fasted condition, the mean (SD) maximum plasma concentration (Cmax) of phenylbutyrate ranged from 146 (30) to 169 (33) μg/mL, which was achieved at approximately 0.6 hour after PHEBURANE administration. The mean (SD) area under the plasma concentrati...

The following adverse reactions associated with the use of sodium phenylbutyrate were identified in clinical studies or postmarketing reports. Because some of these reactions were reported voluntarily and from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Most common adverse reactions (incidence ≥ 3%) are amenorrhea or menstrual dysfunction (irregular menstrual cycles), decreased appetite, body ...

None None. ( 4 )

Neurotoxicity of Phenylacetate : Increased exposure to phenylacetate, the major metabolite of PHEBURANE, may be associated with neurotoxicity in patients with UCDs. Consider reducing the dose if neurotoxicity symptoms are present. ( 5.1 ) Hypokalemia : Renal excretion of phenylacetylglutamine may induce urinary loss of potassium. Monitor serum potassium during therapy and initiate appropriate treatment when necessary. ( 5.2 ) Conditions Associated with Edema : Calculate the total amount of sodiu...

7 DRUG INTERACTIONS Valproic Acid, Haloperidol, or Corticosteroids : May increase plasma ammonia level; monitor ammonia levels closely. ( 7.1 ) Probenecid : May inhibit renal excretion of metabolites of PHEBURANE including phenylacetate and phenylacetylglutamine; monitor for potential neurotoxicity. ( 7.2 ) 7.1 Potential for Other Drugs to Affect Ammonia Corticosteroids Use of corticosteroids may ...