Overall trial timeline. Identical studies were performed before (‘day 1’) and immediately following (‘day 4’) a 3-day course of N-carbamylglutamate at a dose of 100 mg/kg/d or 2.2g/m2/d if ≥25 kg. Plasma samples for ammonia, urea, amino acids and [13C]urea were obtained at T0, 15, 30, 45, 60, 90, 120, 180, and 240 min.