Omeprazole

證據等級: L5

預測適應症: 2 個

One-Sentence Summary

Omeprazole is a proton pump inhibitor (PPI), widely recognized as a first-line treatment for acid-related gastrointestinal conditions including peptic ulcer disease, GERD, and Helicobacter pylori eradication regimens. The TxGNN model predicts it may be effective for Duodenogastric Reflux, with 1 clinical trial and 20 publications currently supporting this direction — though the mechanistic picture is mixed and carries an unresolved safety signal regarding cancer risk potentiation.

Quick Overview

Item	Content
Original Indication	Peptic ulcer / GERD / H. pylori eradication (standard pharmacological use; no Philippines FDA registration on file)
Predicted New Indication	Duodenogastric Reflux
TxGNN Prediction Score	99.64%
Evidence Level	L3
Philippines Market Status	Not Registered
Number of Registrations	0
Recommended Decision	Hold

Why is This Prediction Reasonable?

Currently, detailed mechanism of action data is not available from this Evidence Pack. Based on known pharmacology, Omeprazole is the archetypal H⁺/K⁺-ATPase inhibitor, suppressing gastric acid secretion by irreversibly blocking the final common step of acid production in gastric parietal cells. It is an established first-line agent for peptic ulcer disease, gastroesophageal reflux disease (GERD), and triple-therapy H. pylori eradication regimens.

Duodenogastric reflux (DGR) refers to the retrograde flow of duodenal contents — primarily bile acids and pancreatic enzymes — into the stomach. While Omeprazole cannot directly block bile reflux (which is alkaline by nature), it has been hypothesized to reduce overall mucosal damage in mixed acid-bile reflux by lowering the acid component, and has been studied particularly in Barrett’s esophagus patients where both acid and bile exposure contribute to disease progression. Clinical observational data (PMID 9824338, PMID 10994616) confirm that omeprazole does reduce DGR to some extent, though the bile component persists.

However, the mechanistic case cuts both ways. Animal model studies (PMID 10389684, PMID 33027361) raise a specific concern: gastric acid suppression combined with DGR may potentiate gastric carcinogenesis, likely by altering intragastric microbiome composition and promoting nitrosamine formation in an alkaline, bile-rich environment. This unresolved tension — modest acid-pathway benefit versus potential cancer-risk promotion — is the primary basis for a Hold recommendation until human RCT data clarifies the risk-benefit balance in this specific indication.

Clinical Trial Evidence

Trial Number	Phase	Status	Enrollment	Key Findings
NCT02685150	N/A	Completed	157	Diagnostic imaging study using Endoscopic Tri-Modal Imaging (NBI/AFI/WLI) to differentiate functional dyspepsia from reflux disease (acid and bile reflux). No interventional Omeprazole treatment arm; provides indirect evidence on DGR characterization but does not assess therapeutic benefit.

Literature Evidence

PMID	Year	Type	Journal	Key Findings
9824338	1998	Prospective RCT-like	Gut	Omeprazole 20 mg BID reduces both duodenogastric and gastro-oesophageal bile reflux in Barrett’s oesophagus; DGR decreased but not eliminated — key evidence that PPIs modulate but do not abolish bile reflux.
10994616	2000	Prospective Observational	Scand J Gastroenterol	Long-term omeprazole may reduce antral DGR in Barrett’s patients; however, the resulting high intragastric pH may paradoxically increase cytotoxicity of remaining duodenal refluxate on foregut mucosa.
16641575	2006	Prospective Cohort (Pediatric)	J Pediatr Gastroenterol Nutr	PPI therapy (omeprazole-based) reduces oesophageal bile reflux in children with refractory symptoms; supports use as part of DGR management in paediatric populations.
11552908	2001	Prospective Comparative	Aliment Pharmacol Ther	Pantoprazole (PPI class) effectively reduces acid reflux but has limited impact on the bile component of DGR in oesophagitis patients — highlights the class-wide limitation of PPIs against bile reflux.
9841990	1998	Prospective Comparative	J Gastrointest Surg	Medical acid suppression reduces acid exposure but not bile reflux in Barrett’s esophagus; Nissen fundoplication proved superior for controlling the bile component, suggesting surgery may be needed for full DGR management.
11232672	2001	Observational	Am J Gastroenterol	PPI therapy normalizes acid but not bile reflux in Barrett’s esophagus; combined acid+bile exposure correlates with severity of mucosal disease, reinforcing the partial-efficacy argument for PPIs in DGR.
19491829	2009	Observational	Am J Gastroenterol	GERD patients failing once-daily PPI showed significantly higher duodenogastroesophageal reflux (DGER) than responders; identifies DGER as a distinct mechanism of PPI treatment failure.
33027361	2020	Animal (Rat Model)	Acta Cir Bras	Omeprazole did not protect against gastric adenocarcinoma induced by DGR in rats; raises concern about the interaction between acid suppression and bile-induced carcinogenesis in the DGR context.
10389684	1999	Animal (Rat Model)	Dig Dis Sci	Gastric acid blockade with omeprazole combined with DGR produced significantly higher gastric carcinoma rates than DGR alone in rats — the primary preclinical safety signal against this repurposing direction.
18679668	2008	Review	Eur J Clin Pharmacol	Comprehensive PPI pharmacokinetics and clinical use review; confirms class-wide indication for acid-related disorders while noting limitations in non-acid reflux components.

Philippines Market Information

No Philippines FDA registrations are on file for Omeprazole in this dataset.

Note: This likely represents a data gap rather than true non-availability. Omeprazole is a WHO Essential Medicine and is commercially available in most global markets. A manual verification against the Philippine FDA online drug registration database (www.fda.gov.ph) is strongly recommended before drawing any conclusions about local market status.

Safety Considerations

Please refer to the package insert for safety information.

Critical signal from preclinical literature: Animal studies (PMID 10389684, PMID 33027361) specifically demonstrate that omeprazole in the setting of duodenogastric reflux may promote rather than prevent gastric carcinogenesis. This is mechanistically plausible (alkaline stomach + altered microbiome → nitrosamine formation) and has not been definitively refuted in human data. This signal is a deciding factor in the Hold recommendation.

Conclusion and Next Steps

Decision: Hold

Rationale: Omeprazole can partially reduce the acid component of mixed reflux, but it does not address bile reflux — the primary driver of DGR pathology — and preclinical evidence raises a credible, unresolved concern that acid suppression combined with DGR may potentiate gastric carcinogenesis. The available human evidence is limited to observational studies in Barrett’s esophagus patients (not DGR as a primary endpoint), which is insufficient to define a positive risk-benefit ratio for this specific repurposing direction.

To proceed, the following is needed:

Philippines FDA registration status verification via manual database search
Mechanism of action data retrieval from DrugBank API (currently a data gap)
Human clinical trial data specifically targeting DGR as a primary endpoint with Omeprazole (no such trial currently registered)
Human observational data addressing the carcinogenesis safety signal identified in rat models — particularly long-term PPI use in populations with confirmed DGR
Clarification of the dose and treatment duration required to achieve clinically meaningful DGR reduction in humans
Disclaimer

This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.