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

ABSTRACT

PURPOSE: 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. METHODS: 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 > or =5 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 > or =5 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. RESULTS: 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) microg 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. CONCLUSIONS: 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.