Characterization of the duration of treatment with diazoxide in infants with prolonged hyperinsulinism (PHI)

Background: Prolonged neonatal hyperinsulinism (PHI) causes hypoglycemia in the neonatal period and is associated with perinatal stress. Even though diazoxide is an effective treatment option for PHI, it has serious adverse effects making an argument for safe yet expeditious wean off of diazoxide while ensuring normoglycemia. The objective of this study was to characterize clinical course, dose requirement and duration of treatment with diazoxide in our cohort of infants diagnosed with PHI. Methods: A retrospective chart review of infants diagnosed with PHI during a 6-year period was done documenting the diagnostic workup and the duration of treatment with diazoxide. Results: PHI was diagnosed (n = 20; mean +/- standard deviation [SD]) at 14.3 +/- 22.4 days. Elevated insulin (8.3 +/- 8.4 mIU/L), normal cortisol (15.5 +/- 6.6 pg/dL [6 21]), normal growth hormone (18.8 +/- 15.7 ng/mL [0.1-6.2]) and inappropriate low serum free fatty acids (0.3 +/- 0.2 mmol/L [>1.5]) levels were measured during hypoglycemia (plasma glucose <50 mg/dL). Detectable insulin at the time of hypoglycemia was measured in 17 of 20 infants while the same number (17/20) of infants had a positive glucagon stimulation test (GST). The dose of diazoxide was 10 +/- 3.7 mg/kg/day and duration of treatment was 44.9 +/- 279 days. Conclusions: This study illustrates that the duration of treatment with diazoxide in infants with PHI can be shorter than previously reported in the literature. We speculate that active tapering of diazoxide started within a week after discharge from hospital as well an outpatient tapering of diazoxide based on glucose monitoring were possible reasons for this outcome.