Sublingual Administration of Desmopressin Oral Disintegrating Tablet in a Neonate With Central Diabetes Insipidus.

Precise titration of desmopressin (1-deamino-8-D-arginine vasopressin; DDAVP) is essential for managing neonatal central diabetes insipidus (CDI). Although oral administration is increasingly considered an alternative to the traditional intranasal route, the differences between DDAVP formulations and administration methods are often unclear in clinical practice. This complicates efforts to establish effective sublingual treatment protocols using oral disintegrating tablets (ODTs) in neonates. Here, we present the case of a Japanese neonate with CDI, semilobar holoprosencephaly, and a cleft lip and palate. The patient exhibited hypotonic polyuria, hypernatremia, elevated serum osmolality, and low plasma arginine vasopressin (AVP) levels within the first week of life. At 30 days of age, we dissolved a 60-µg DDAVP ODT in 5 mL of water and administered it sublingually. The initial dose of 3 µg/kg/day was titrated to 2 µg/kg/day based on the patient's clinical response. Close monitoring enabled fine adjustment of dosing. The patient achieved a stable fluid balance and did not exhibit signs of hyponatremia, seizures, or other adverse events. This case supports the potential utility of sublingual DDAVP ODTs in neonates and underscores the necessity of establishing standardized preparation and dosing protocols, which will require further clinical experience.