Drug General Information (ID: DDIL8SAMZF)
Drug Name			Phenobarbital		Drug Info		Glycerol phenylbutyrate		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Anticonvulsants				Urea Cycle Disorder Agents
Structure

Mechanism of Phenobarbital-Glycerol phenylbutyrate Interaction (Severity Level: Moderate)
Increased risk of hyperammonemia Click to Show/Hide Mechanism Graph
Drug Name		Phenobarbital				Glycerol phenylbutyrate
Mechanism		Hyperammonemia				Hyperammonemia
Key Mechanism Factor 1
		Factor Name		Hyperammonemia
		Factor Description		Hyperammonemia is a metabolic disorder characterized by elevated levels of ammonia. The most common manifestations of hyperammonemia are neurological signs and symptoms that may be acute or chronic, depending on the underlying abnormality, and severe life-threatening complications such as cerebral edema and brain herniation can occur.
Mechanism Description		Increased risk of hyperammonemia by the combination of Phenobarbital and Glycerol phenylbutyrate

Recommended Action
Management		Plasma ammonia levels should be closely monitored when corticosteroids, haloperidol, carbamazepine, topiramate, or phenobarbital are used in patients with urea cycle disorders receiving phenylbutyrate therapy.

References
1	Cerner Multum, Inc. "Australian Product Information.".
2	Product Information. Buphenyl (sodium phenylbutyrate). Horizon Pharma USA Inc, Northbrook, IL.
3	Product Information. Ravicti (glycerol phenylbutyrate). Hyperion Therapeutics Inc, South San Francisco, CA.