Use of carglumic acid in the treatment of hyperammonaemia during metabolic decompensation of patients with propionic acidaemia

Propionic acidaemia (PA) results from propionyl-CoA carboxylase deficiency. During metabolic decompensation, the accumulation of propionyl-CoA causes secondary hyperammonaemia through N-acetylglutamate synthetase inactivation. Carglumic acid, a structural analogue of N-acetylglutamate, was given to patients with PA (n = 3) during episodes of metabolic decompensation (n = 8; age range: birth to 4 years), in addition to high energy/low protein intake and carnitine. Plasma ammonia concentrations normalised within 6-19 h. Carglumic acid was well tolerated with no side effects noted.