A New Frontier in GERD: The Gastric Pocket

Jeannette Y. Wick, RPh, MBA, FASCP
Published Online: Friday, June 6, 2014
Follow Pharmacy_Times:
Researchers examined the effects of proton pump inhibitors on the highly acidic pocket of gastric juice at the esophagogastric junction.

The gastric acid pocket is an area of unbuffered, highly acidic gastric juice that forms at the esophagogastric junction after meals. It floats between 2 less acidic layers of stomach juices. Experts describe it as the reservoir from which acid reflux events originate. The gastric pocket was only identified in 2001, so researchers still have many questions about its function and effects.

Since little is known about how the acid pocket’s position, size, and acidity affect therapeutic effects of proton pump inhibitors (PPIs) in patients with gastroesophageal reflux disease (GERD) and vice versa, this is an area of interest. A team of researchers has published a study examining this issue in the May 2014 issue of Clinical Gastroenterology and Hepatology.

The researchers enrolled 36 GERD patients in this study designed to look at how the gastric pocket interacts with PPIs. Among the study participants, half were not taking PPIs and the remainder were taking various PPIs. The researchers analyzed each participant’s stomach using high-resolution manometry and pH-impedance monitoring after a standardized meal. They also used scintigraphy after intravenous administration of 99mtechnetium-pertechnetate to visualize the acid pocket. Ultimately, they aspirated the acid pocket to measure its pH level.

Patients who took PPIs had significantly fewer acid reflux episodes than those who did not. PPI-treated patients had smaller acid pockets that were more often located below the diaphragm. The mean pH of the acid pocket was significantly higher in PPI-treated patients not taking PPIs and its pH was similar to the pH measured in patients’ refluxate.

From their observation, the researchers concluded:
  • PPI treatment causes gastric secretions to accumulate on top of ingested food and form a pocket.
  • PPIs increase the pH of refluxate, and if the acid pocket’s pH is higher (less acidic), the refluxate’s pH is also.
  • PPI treatment reduces the size of the acid pocket, explaining why the acid pocket is located below the diaphragm more often during the use of PPIs.
They conclude that the acid pocket appears to be a reservoir from which reflux occurs during treatment with PPIs. PPIs might affect the size, acidity, or position of the acid pocket, which contributes to their efficacy in patients with GERD. The acid pocket may be the source of refractory symptoms.

Ms. Wick is a visiting professor at the University of Connecticut School of Pharmacy and a freelance writer from Virginia.
Related Articles
The FDA today approved Ivax Pharmaceuticals’ esomeprazole magnesium delayed-release capsules, the first generic version of AstraZeneca’s proton pump inhibitor Nexium, for the treatment of gastroesophageal reflux disease in patients aged >1 year.
After ringing in the New Year, Americans from all walks of life have started dieting. For the 10% to 20% of Americans who experience gastric reflux, such weight loss may be the key to reducing associated symptoms.
A recent review of inappropriate prescribing among hospitalized older adults revealed that proton pump inhibitors follow only opiates and benzodiazepines as the most frequently misprescribed medications.
A new Mayo Clinic study published in Microbiome shows that patients with acid reflux who regularly receive proton pump inhibitors have less diverse gut bacteria, which heightens their risk for bone fractures, vitamin deficiencies, and infections such as Clostridium difficile and pneumonia.
Latest Issues
  • photo
    Pharmacy Times
    Health-System Edition
    Directions in Pharmacy
    OTC Guide
    Generic Supplements
  • photo
    Pharmacy Careers
    Specialty Pharmacy Times