Impact of sodium phenylbutyrate treatment in acute management of maple syrup urine disease attacks: a single-center experience

J Pediatr Endocrinol Metab. 2020 Nov 11;34(1):121-126. doi: 10.1515/jpem-2020-0356. Print 2021 Jan 27.


Objectives: Accurate management of metabolic decompensation in maple syrup urine disease (MSUD) has a crucial role, as acute attacks can cause neurological sequels and can be life threatening. Here, we aimed to evaluate effect of sodium phenylbutyrate (NaPBA) in acute management of MSUD attacks.

Methods: Episodes with an initial plasma leucine (Leu) level above 750 µmoL/L and that require hospitalization due to clinical findings of Leu neurotoxicity and/or feeding difficulties were included to the study. Patients who had no molecular diagnosis and a regular follow-up were excluded. Clinical findings, laboratory results and therapy responses were reviewed, retrospectively.

Results: Ten patients who experienced 19 distinct episodes of MSUD attacks were enrolled. Initial median Leu level was 901.67 (range 756-1989.11) and 33.9 µmoL/L (range 7.91-347.3 µmoL/L) at the end of therapy. None of our patients underwent extracorporeal toxin removal during the course of attack. In patients with serial plasma quantitative amino acid sampling, mean Leu reduction rate was calculated to be 529.68 ± 250.08 µmoL/L/day at the 24th h of treatment and 318.72 ± 191.52 µmoL/L/day at the 48th h of treatment.

Conclusions: This study is the first original study that investigates the effect of NaPBA in management of acute attacks of MSUD patients from Turkey. We suggest that NaPBA treatment in MSUD attacks can ameliorate clinical and biochemical findings. This therapeutic option should be considered especially in smaller centers without the toxin removal chance and for patients who were not appropriate for extracorporeal toxin removal like hemodynamic instability.

Keywords: CRRT; MSUD; emergency treatment; extracorporeal toxin removal; sodium phenylbutyrate.

Publication types

  • Clinical Trial

MeSH terms

  • Antineoplastic Agents / therapeutic use*
  • Child
  • Child, Preschool
  • Disease Management
  • Female
  • Follow-Up Studies
  • Humans
  • Infant
  • Male
  • Maple Syrup Urine Disease / drug therapy*
  • Maple Syrup Urine Disease / pathology
  • Phenylbutyrates / therapeutic use*
  • Prognosis
  • Retrospective Studies


  • Antineoplastic Agents
  • Phenylbutyrates
  • 4-phenylbutyric acid