The aim of this study was to systematically review the use of vaptans (nonpeptide vasopressin receptor antagonists) in children.
Through a database search (Web of Science, the National Library of Medicine, Excerpta Medica), we identified case series and case reports and extracted clinical and laboratory data.
Twenty-six articles, published since 2008, reported on 226 patients. Among 115 children with hyponatraemic (n = 63) and oedematous disorders (n = 52), a 48 hour course of tolvaptan with an initial dose of 0.38 ± 0.27 mg/kg was administered in 106 cases, while intravenous conivaptan was reported in nine cases. An increase (P < .02) in urine output was shown in both oedematous (from 3.2 ± 2.0 to 5.3 ± 6.7 mL/kg/day) and hyponatraemic (from 3.0 ± 1.5 to 4.4 ± 2.3 mL/kg/day) patients. In these latter, sodium increased from 125 ± 6 to 133 ± 6 mmol/L (P < .0001). The increase in sodium level correlated with its basal value, but not with the administered vaptan dose. Among 111 children undergoing cardiac surgery, after tolvaptan 0.21 ± 0.01 mg/kg/day, mostly combined with conventional diuretics, an increase in diuresis by 41 ± 4% was seen within 24 hours (P < .0001). Similarly, a single add-on dose of tolvaptan 0.45 mg/kg allowed a reduced additional intravenous furosemide administration (0.26 ± 0.23 vs 0.62 ± 0.48 mg/kg, P < .005). Side effects were rarely reported, and included excessive thirst and xerostomia in seven, skin rash in one and elevated aminotransferases in one patient(s).
Vaptans appear to be safe for oedematous and hyponatraemic disorders also in children. Although they increase diuresis and natraemia, no superiority to traditional diuretics and sodium supplements has been demonstrated. Reported side effects are rare and non-serious.