Treatment should be coordinated by a metabolic specialist and is based on reducing plasma ammonia and arginine concentration, preventing excess ammonia from being formed, and reducing the amount of nitrogen in the diet.
Reduction of plasma ammonia concentration is accomplished by dialysis and several different methods are available. This should be used only when the high levels are producing severe symptoms.
The nitrogen scavenger drugs sodium phenylacetate and sodium benzoate provide an alternative pathway for removing excess nitrogen. Intravenous and oral forms of these medications are available (Ammonul). Phenylbutyrate (Buphenyl) has a less offensive odor than the other medications but is available as oral therapy only. Ravicti is a form of phenylbutyrate that is less irritating to the gastrointestinal track and easier to take.
Dietary restrictions in individuals with arginase-1 deficiency are aimed at limiting the amount of arginine and protein intake. Children with arginase-1 deficiency are placed on a low-protein, arginine-restricted diet supplemented by essential amino acids.
Seizures are treated with phenobarbital or carbamazepine. Valproic acid should be avoided, as it can increase blood ammonia levels.
Affected individuals should receive periodic blood tests to determine the levels of ammonia and arginine in the blood and to be sure that liver function is not impaired. Excessive levels of ammonia or arginine should be promptly treated.
Genetic counseling is recommended for affected individuals and their families.