Pharmacokinetics of single and repeated oral doses of esomeprazole and gastrin elevation in healthy males and females.

Objective: Gastrin elevation secondary to proton pump inhibitor (PPI) therapy is well documented. Recent studies have demonstrated a sex-related difference where females on PPIs have significantly higher baseline gastrin levels than males. The aim of the study was to analyse the pharmacokinetics of esomeprazole and short-term effect on serum gastrin levels and evaluate potential sex-related difference.

Materials And Methods: Healthy volunteers received 40 mg of esomeprazole daily for five days. After the 1st and 5th dose blood samples for fasting gastrin and pharmacokinetic analysis were collected at scheduled time-points for eight hours. Esomeprazole was analysed by liquid chromatography and gastrin concentrations were measured using radioimmunoassay.

Results: A total of 30 volunteers were enrolled. Females had higher median baseline gastrin (pM) than males 12 (IQR 10-15) vs. 7 (IQR 4-11) ( = .03). In the study cohort, median gastrin levels rose from 10 (IQR 6-14) to 15 (IQR 13-20) ( = .0002). The serum levels for esomeprazole increased by an average of 299.8 ng/mL ( < .001) from day 1 to day 5. Comparison of the esomeprazole pharmacokinetic parameters between males and females revealed no significant sex-related differences. No significant correlation was found between the AUC and the gastrin level on day 5 ( = .15).

Conclusions: In healthy volunteers, serum gastrin increased significantly after a four-day PPI-therapy. There was also a significant increase in serum esomeprazole from day 1 to day 5. The increase in gastrin and esomeprazole concentration was not related to sex and no significant sex-related difference was found in terms of pharmacokinetic parameters. European Clinical Trial Database (2015-002230-41).