Management Challenges in a Child with Chronic Hyponatremia: Use of V2 Receptor Antagonist

Table 2

Clinical course with initiation of tolvaptan therapy.

Timeline	Weight; (Kg)	Sodium; (mEq/L)	Tolvaptan dose	Serum osmolality; (mOsm/Kg)	Urine osmolality; (mOsm/Kg)	AVP; (pg/mL)
Prior to initiation of tolvaptan therapy	24.7	121	None	263	428	11.1
Day 2 of initiation of therapy	24.8	127	7.5 mg		26	43.4
6 months after initiation	25.6	123	Increased to 15 mg	250	55	3.0
7 months after initiation	25.9	123	Increased to 22.5 mg
17 months after initiation	26	119	Increased to 30 mg	253		19.5
24 months after initiation	28.6	124	Tolvaptan gradually stopped
1 year after stopping tolvaptan therapy	31.4	118-119	None	235	242	2.2