Iatrogenic neonatal hyperphosphatemia due to phosphate-containing enema.

Summary: Functional constipation is a common condition in infants. Phosphate-containing enemas (PCEs) are contraindicated in neonates due to the significant risk of severe electrolyte disturbances. We report a case of a 28-day-old neonate presenting with constipation and vomiting following the administration of PCEs. This resulted in hyperphosphatemia, hypocalcemia, and a prolonged QTc interval - critical conditions requiring urgent intervention. Management included hyperhydration, intravenous calcium gluconate, and oral alfacalcidol, which led to complete clinical recovery within 60 h. This case underscores the serious risks associated with inappropriate use of over-the-counter PCEs in neonates, even in the absence of underlying health conditions. It also highlights the importance of early recognition and effective supportive therapy to mitigate potential life-threatening complications. Learning points: Irritability and ECG anomalies can be the only signs and symptoms of severe acute hyperphosphatemia after administration of PCE. Clinicians should be aware of the risk of severe acute hyperphosphatemia after PCE administration in infants, even without comorbidities, due to a low PTH status. When symptomatic hypocalcemia occurs, intravenous calcium administration is warranted, as the risk of life-threatening consequences from hypocalcemia significantly outweighs the risk of developing metastatic calcifications.