Single-dose, multiple-dose, and population pharmacokinetics of pantoprazole in neonates and preterm infants with a clinical diagnosis of gastroesophageal reflux disease (GERD)

The pharmacokinetic profile of pantoprazole granules was assessed in neonates and preterm infants with gastroesophageal reflux disease (GERD) in a multicenter, randomized, open-label trial. Patients were randomly assigned to either the pantoprazole 1.25 mg (approx. 0.6 mg/kg) or 2.5 mg (approx. 1.2-mg/kg) group and treated for a parts per thousand yen5 consecutive days. Blood was sampled either at 0, 2, 8, and 18 h postdose or at 0, 1, 4, and 12 h postdose on day 1 and at 3 and 6 h postdose after a parts per thousand yen5 consecutive doses. Cytochrome P450 2C19 (CYP2C19) and CYP3A4 genotypes were determined. Safety was monitored. Population pharmacokinetics (popPK) analyses were conducted using nonlinear mixed-effects modeling. The popPK modeling of the pantoprazole 1.25 mg and 2.5 mg groups obtained mean (+/- standard deviation) estimates for the area under the plasma concentration versus time curve (AUC) of 3.54 (+/- 2.82) and 7.27 (+/- 5.30) A mu g h/mL, respectively, and mean estimates for half-life of 3.1 (+/- 1.5) and 2.7 (+/- 1.1) h, respectively. Pantoprazole did not accumulate following multiple-dose administration. The two patients with the CYP2C19 poor metabolizer genotype had a substantially higher AUC than extensive metabolizers. No safety-related discontinuations occurred. In preterm infants and neonates, pantoprazole granules were generally well tolerated, mean exposures with pantoprazole 2.5 mg were slightly higher than that in adults who received 40 mg. While the half-life was longer, accumulation did not occur.