Clinical experience with spironolactone in pediatrics.

BACKGROUND: In 2003, the Food and Drug Administration placed spironolactone on its list of drugs needing pediatric studies.

OBJECTIVE: To describe the use of spironolactone in a large group of children and evaluate its safety, focusing on its effects on potassium.

METHODS: A prospective observational study was conducted. Patient demographic information was collected, as well as dosing regimens, use of other medications, and potassium concentrations. Patients were grouped by diagnosis. Comparisons were made with unpaired t-tests.

RESULTS: One hundred consecutive patients were evaluated. The average age was 20.8 months and weight was 9.5 kg. Sixty-two patients had heart disease (HD), 29 had chronic lung disease (CLD), and 9 had other conditions. The initial dose was 1.8 +/- 0.7 mg/kg/day. Patients with CLD received a higher dose than those with HD (2 +/- 0.8 vs 1.7 +/- 0.5 mg/kg/day; p = 0.04). Sixty-six patients received furosemide and 37 received thiazides (12 received both). The average potassium concentration after initiation was 4.3 +/- 0.8 mEq/L, with higher values in patients with CLD versus HD (4.7 +/- 0.7 vs 4.2 +/- 0.7 mEq/L; p = 0.007). Twenty-six patients required potassium supplementation, including 16 with CLD and 8 with HD; no other adverse effects were noted. Average length of treatment was 16 days, with a length of stay of 38 days. Of the 92 patients surviving to discharge, 66 continued on spironolactone.

CONCLUSIONS: This sample demonstrates that spironolactone is a common component of diuretic regimens in pediatric patients. The only adverse effects were alterations in potassium. While hyperkalemia was more common initially, hypokalemia was more frequent with long-term use. Potassium concentrations should be carefully monitored, particularly in children receiving multiple diuretics. Additional research is needed to define the pharmacokinetics and optimal dosing interval of spironolactone, as well as determine its long-term effects on potassium.