Famotidine
| Evidence Level: L3 | Predicted Indications: 10 |
Table of Contents
Famotidine: From Acid Suppression (H2-Receptor Antagonist) to Duodenogastric Reflux
One-Sentence Summary
Famotidine is a histamine H2-receptor antagonist that lowers gastric acid output. The TxGNN model predicts it may help with duodenogastric reflux, but there are 0 registered clinical trials and only 2 publications, both small clinical studies that do not report outcomes in the material provided. Evidence for this specific indication is weak.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Not available (the US approval records provided contain no indication text) |
| Predicted New Indication | Duodenogastric reflux |
| TxGNN Prediction Score | 99.99% |
| Evidence Level | L3 |
| US Market Status | ✓ Marketed |
| Number of NDAs | 20 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data is not available from DrugBank. The rationale below therefore rests on the known pharmacology of famotidine, which blocks H2 receptors on gastric parietal cells and reduces acid secretion.
Duodenogastric reflux is the backflow of duodenal contents into the stomach. Lowering acid could reduce mucosal injury caused by the refluxed material. This benefit is plausible only for the acid component. Bile and alkaline reflux are not acid-driven, so famotidine would not be expected to address them directly.
The prediction is therefore mechanistically credible but partial. At best, famotidine would ease acid-related damage and symptoms rather than stop the reflux itself.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 12532466 | 2003 | Clinical study | World J Gastroenterol | Examined the effect of famotidine on gastroesophageal and duodeno-gastro-esophageal reflux in critically ill patients and explored possible mechanisms and related factors. Only the study aim is available, with no results. |
| 16259441 | 2004 | Clinical study / Review | Eksp Klin Gastroenterol | Assessed famotidine 20 mg twice daily in early-stage gastroduodenal reflux disease (Savary-Miller grades 0–1) using clinical and endoscopic evaluation. Only the study aim is available, with no results. |
Neither publication is confirmed as a randomized controlled trial, and neither abstract states an efficacy result.
US Market Information
The 20 listed authorizations are all generic (ANDA) products. The first 5 are shown below. No approved indication text is available in the source records.
| Authorization Number | Product Name | Dosage Form |
|---|---|---|
| ANDA075786 | famotidine (Chartwell RX, LLC) | Film-coated tablet |
| ANDA078916 | Famotidine (NCS HealthCare of KY, dba Vangard Labs) | Tablet |
| ANDA075511 | Famotidine (Northwind Health Company, LLC) | Film-coated tablet |
| ANDA201995 | Famotidine (Akorn) | Powder for solution |
| ANDA206531 | Zantac 360, Travel BASIX (Lil’ Drug Store Products, Inc) | Film-coated tablet |
Safety Considerations
Please refer to the package insert for safety information.
Conclusion and Next Steps
Decision: Hold
Rationale: The TxGNN score is very high, but the evidence for duodenogastric reflux is thin. There are no registered trials and only two small clinical studies with no reported outcomes. The plausible mechanism covers only the acid component of the reflux. This is a research question rather than an actionable candidate.
To proceed, the following is needed:
- Full-text review of PMID 12532466 and 16259441 to confirm study design, endpoints and results
- A controlled study with defined endpoints such as symptom relief and mucosal injury, separating acid from bile or alkaline reflux
- DrugBank mechanism of action data and the package insert warnings and contraindications
- Original indication text for the US approvals, to complete the baseline comparison
Other predictions for famotidine, such as peptic ulcer disease, are established uses of the drug and are not treated as novel repurposing here.
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.