https://pubmed.ncbi.nlm.nih.gov/12018920/#:~:text=In%20conclusion%2C%20esomeprazole%2040%20mg,the%20standard%20dose%20of%20omeprazole.

Abstract

Maintenance of intragastric pH > 4 is vital for effective management of gastroesophageal reflux disease (GERD). Esomeprazole 40 mg, the first proton pump inhibitor developed as an optical isomer, demonstrates improved acid inhibition over omeprazole 20 mg. Our aim was to compare esomeprazole 40 mg with omeprazole 40 mg, once-daily, on intragastric acidity in patients with symptoms of GERD. In this open-label, crossover study, 130 patients with symptoms of GERD received esomeprazole 40 mg or omeprazole 40 mg once-daily for five days. The 24-hr intragastric pH was monitored on days 1 and 5 of each treatment period. The mean percentage of the 24-hr period with intragastric pH > 4 was significantly greater (P < 0.001) with esomeprazole 40 mg than with omeprazole 40 mg on days 1 (48.6% vs 40.6%) and 5 (68.4% vs 62.0%). Interpatient variability was significantly less with esomeprazole than omeprazole. Esomeprazole was well tolerated. In conclusion, esomeprazole 40 mg provides more effective acid control than twice the standard dose of omeprazole.