title: A randomized, crossover pharmacodynamic study of immediate-release omeprazole/sodium bicarbonate and delayed-release lansoprazole in healthy adult volunteers.
abstract: Proton pump inhibitors (PPIs) effectively block gastric acid secretion and are the treatment of choice for heartburn. PPIs differ, however, in onset of action and bioavailability. In this single-center, open-label, three-way crossover study, onset of action of immediate-release omeprazole 20 mg/sodium bicarbonate 1100 mg (IR-OME) and delayed-release (DR) lansoprazole 15 mg was evaluated in 63 healthy fasting adults. Subjects were randomized to once daily IR-OME, or DR-lansoprazole, or no treatment for 7 days. The primary efficacy endpoint was the earliest time where a statistically significant difference was observed between IR-OME and DR-lansoprazole in median intragastric pH scores for three consecutive 5-min intervals on day 7. Secondary endpoints compared effects of active treatments on days 1 and 7 (e.g., time to sustained inhibition, percentage of time with pH >4). A significant difference in median intragastric pH favoring IR-OME was observed on day 7 starting at the 10- to 15-min interval postdosing (P = 0.024) and sustaining through the 115- to 120-min interval (P = 0.017). On day 1, IR-OME achieved sustained inhibition of intragastric acidity significantly faster than DR-lansoprazole. IR-OME maintained pH >4 significantly longer than DR-lansoprazole over a 24-h period (P = 0.007) on day 7. Overall, results of this study demonstrate IR-OME is safe and well tolerated and that treatment with IR-OME results in significantly faster onset of action and better gastric acid suppression at steady state than DR-lansoprazole.
authors.affiliation: Clinical Applications Lab., Inc. San Diego California.
authors.forename: Vijayalakshmi S
authors.initials: VS
authors.lastname: Pratha
authors.affiliation: Merck & Co. Kenilworth New Jersey.
authors.forename: Thomas
authors.initials: T
authors.lastname: McGraw
authors.affiliation: International HealthCare, LLC Norwalk Connecticut.
authors.forename: William
authors.initials: W
authors.lastname: Tobin
keywords: Crossover study; delayed‐release lansoprazole; efficacy; immediate‐release omeprazole/sodium bicarbonate; pharmacodynamics; safety