Elevation of pivaloylcarnitine by sivelestat sodium in two children

Abstract Background Sivelestat sodium (sivelestat), a neutrophil elastase inhibitor, is used to treat acute respiratory distress syndrome (ARDS). We report two cases that developed elevated C5-acylcarnitine (C5-AC) levels following treatment with sivelestat. Case 1 was a 14-day-old female infant born at 25 weeks and 1 day of gestation who was treated with sivelestat for the prophylaxis of Wilson–Mikity syndrome soon after birth. Isovaleric acidemia (IVA) was suspected based on a newborn screening using tandem mass spectrometry (MS/MS). Her C5-AC level was elevated to 4.49 μM (cut-off, Results In both cases, IVA was ruled out because isovalerylglycine was not observed in the urinary organic acid analysis. Case 1 was associated with carnitine deficiency (C0 9.16 μM; reference value, 10–60). Liquid chromatography-MS/MS confirmed elevated pivaloylcarnitine (PVC) in both cases. Discussion Similar to antibiotics containing pivalic acid (PVA), sivelestat contains PVA, which has the potential to cause secondary carnitine deficiency. In addition, elevated PVC can lead to false positive findings of IVA in newborns screened using MS/MS.