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Table 8 Dosages of peroral drugs for long-term treatment of UCDs

From: Suggested guidelines for the diagnosis and management of urea cycle disorders

Disorder Sodium benzoatea Sodium PBAa,b L-Argininea (hydrochloride or free base) L-Citrullinea Carbamyl- glutamatea
NAGSD 10–100 mg/kg/d
CPS1D ≤ 250mg/kg/dc,d maximum: 12g/d <20 kg: ≤250mg/kg/dc,d >20 kg: 5g/m2/d maximum: 12g/day <20 kg: 100-200mg/kg/dc(0.5-1mmol/kg/d) >20 kg: 2.5-6g/m2/d maximum: 6g/d 100-200mg/kg/de maximum: 6g/d
OTCD same same same same
ASSD same same <20 kg: 100-300mg/kg/dc,d>20 kg: 2.5-6g/m2/d maximum: 6g/d
ASLD same same
ARG1D same same
HHH syndrome same same <20 kg: 100-200mg/kg/dc >20 kg: 2.5-6g/m2/d maximum: 6g/d same
  1. All medications should be divided into three to four equal daily doses taken with meals and distributed as far as possible throughout the day. Grade of recommendation, C-D.
  2. a100 mg of each drug correspond to the following amounts in mmols: 0.694 sodium benzoate; 0.537 sodium PBA; 0.475 arginine hydrochloride; 0.574 arginine base; 0.571 citrulline; 0.532 carbamylglutamate.
  3. b Sodium PBA was considered of second choice for long-term treatment by most guideline group members. It should be given together with sodium benzoate in patients in which benzoate alone is not enough.
  4. c Serum/plasma levels of benzoate/PBA and plasma levels of arginine (aim are fasting levels of 70–120 μmol/L) should be monitored to adjust dosages and in case of high or repeated doses.
  5. d In some patients higher doses are needed, according to expert advice. For PBA, FDA and EMA approved doses are 450-600mg/kg/d in children of <20kg, and, above 20 kg bw, 9.9-13 g/m2/d.
  6. e Citrulline may be preferable. When given no need for concomitant use of L-arginine.