Abstract
The guideline on the dosing of Epoprostenol sodium (PGI2) was established based on data for adults. In order to study the dosing regimen in children in Japan, we followed-up 7 patients under 16 years old with primary pulmonary hypertension (PPH) who received PGI2 and analyzed their doses, hemodynamic parameters and brain natriuretic peptide (BNP) levels. The mean initial dose of PGI2 was 2.0±0.7 ng/kg/min and increases in the PGI2 dosage occurred mostly within 2 weeks of the start of administration. Up to 28 days after starting administration, the mean interval between dose increases was 2.9±3.3 days and the mean dosage increase increment was 0.8±0.4 ng/kg/min. Up to 3 months after starting administration, there was no statistically significant difference in doses between adults and children. Among severe adverse effects reported in acute dose-ranging in Japan, 7 of 18 cases were in children and the initial doses in 4 of them were over 2 ng/kg/min. Based on these findings, appropriate dosing of PGI2 in children is considered to be as follows : 1) The initial dose should be 0.5 ng/kg/min, 2) The dosage increase interval should be over 2 days and the dosage increase increment between 0.5 and 1 ng/kg/min, 3) Up to 3 months, the dose in children may be increased to the same extent as in adults.
