The effects of lansoprazole on erosive reflux oesophagitis are influenced by CYP2C19 polymorphism.

Background: The acid suppressive effect of lansoprazole is influenced by the P450 2C19 (CYP2C19) polymorphism.
Aim: To investigate whether the CYP2C19 genotype is related to the healing of erosive reflux oesophagitis during treatment with lansoprazole.
Methods: Eighty-eight Japanese patients with erosive reflux oesophagitis were treated with a daily oral dose of 30 mg lansoprazole for 8 weeks. The CYP2C19 genotype, Helicobacter pylori infection status and serum pepsinogen I/II ratio were assessed before treatment. At 4 and 8 weeks, the healing of erosive reflux oesophagitis was evaluated endoscopically.
Results: The healing rates were 57.1%, 69.2% and 72.7% at 4 weeks and 77.4%, 95.0% and 100% at 8 weeks in homozygous extensive metabolizers, heterozygous extensive metabolizers and poor metabolizers, respectively. At 8 weeks, the healing rate of erosive reflux oesophagitis was significantly lower in homozygous extensive metabolizers than in the other two groups (P < 0.05). The H. pylori status and serum pepsinogen I/II ratio had less influence than CYP2C19 polymorphism on the healing rate of erosive reflux oesophagitis.
Conclusions: The therapeutic effect of lansoprazole on erosive reflux oesophagitis is influenced by the CYP2C19 genotype status. Therefore, a test of CYP2C19 genotype may be useful for the medical treatment of reflux oesophagitis with lansoprazole.