Lansoprazole in children: pharmacokinetics and efficacy in reflux oesophagitis

Background: Data on the proton pump inhibitor lansoprazole in paediatric patients are limited. Aim: To investigate the pharmacokinetics, optimal dosage and efficacy of lansoprazole in paediatric patients. Methods: A 24-h gastric pH recording and a pharmacokinetic study were performed after 7 days of lansoprazole, 17 mg/m(2) in 23 patients with reflux oesophagitis (median age, 3.5 years). Response was defined as pH > 3 for > 65% of the recording. The dosage was doubled in non-responders. Patients with no response on day 14 were excluded. Responders underwent endoscopy after 4 weeks on the response-inducing dosage; abnormal findings led to a repeat endoscopy after four additional weeks. Results: Nine patients responded to 17 mg/m(2) and six to 30.3 mg/m(2). On day 7, time with pH > 3 was significantly correlated with the area under the plasma concentration-time curve (P = 0.003). The area under the plasma concentration-time curve was significantly greater in the nine responders to 17 mg/m(2) than in the 14 other patients. Pharmacokinetic parameters were similar in responders and non-responders to the higher dose. After 4 weeks, oesophagitis was healed in 80% of responders. Adverse events occurred in three patients and required treatment discontinuation in one. Conclusions: Lansoprazole is effective and safe in children. The optimal starting dosage is 30 mg/m(2) or 1.4 mg/kg.