Identification of benzoylcarnitine in the urine of a patient of hyperammonemia.

SAKUMA, T., ASAI, K., ICHIKI, T., SUGIYAMA, N., KIDOUCHI, K. and WADA, Y. Identification of Benzoylcarnitine in the Urine of a Patient of Hyperammonemia. Tohoku J. Exp. Med., 1989, 159 (2), 147-151-Benzoylcarnitine was identified in the urine of a patient with a carbamoyl-phosphate synthase I deficiency for whom sodium benzoate and L-carnitine had been used to treat hyperammonemia. This is a newly identified metabolite of benzoate. Its excretion in the urine was increased day by day at the administration of both sodium benzoate and L- carnitine from 0.10 to 2.25mmol/g creatinine. Since there is the possibility of a secondary carnitine deficiency and an increase of benzoyl toxicity after long-term therapy with benzoate supplementation and protein restriction, it is important to monitor the urinary excretion of benzoylcarnitine.