Loperamide
| Evidence Level: L5 | Predicted Indications: 10 |
Table of Contents
- Loperamide
- Pharmacist Assessment Report
- Loperamide: From Diarrhoeal Disease to Acute Contagious Conjunctivitis
- One-Sentence Summary
- Quick Overview
- Why is This Prediction Reasonable?
- Clinical Trial Evidence
- Literature Evidence
- Australia Market Information
- Safety Considerations
- Conclusion and Next Steps
- Disclaimer
Loperamide: From Diarrhoeal Disease to Acute Contagious Conjunctivitis
One-Sentence Summary
Loperamide is an antimotility agent originally used to treat diarrhoeal disease and dysentery. The TxGNN model predicts it may be effective for acute contagious conjunctivitis, but there are currently 0 clinical trials and 0 publications supporting this direction. The score comes from the TxGNN model (deep learning) and may reflect similarities the model learned between related diseases, not biological evidence.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Diarrhoeal disease; dysentery |
| Predicted New Indication | Acute contagious conjunctivitis |
| TxGNN Prediction Score | 0.9997 |
| Evidence Level | L5 |
| Australia Market Status | Listed on the PBS Schedule (1 of 1 items) – TGA (ARTG) registration status is not included in this data |
| Number of PBS Items | 1 (valid: 1) |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data is not available in the data compiled for this report. Loperamide is generally understood to be a peripheral mu-opioid receptor agonist acting on gut myenteric neurons, slowing intestinal motility. It is not an anti-infective or an ocular agent.
The review of the prediction found no plausible mechanistic link between loperamide and acute contagious conjunctivitis. The high TxGNN score comes from the TxGNN model (deep learning) and may reflect similarities the model learned between related diseases, not biological evidence. The same pattern appears across the other top-ranked predictions: several conjunctival terms (parasitic, follicular, serous, pseudomembranous conjunctivitis, conjunctival folliculosis) share identical or near-identical scores, which is consistent with similarities the model learned between related diseases.
Other predictions in the top 10 were also reviewed. Only two had any literature, and both were safety signals rather than efficacy evidence:
- Amoebic dysentery: A 2007 case report described fulminant amoebic colitis following heavy loperamide use. Loperamide treats the symptom, not the Entamoeba histolytica infection, and slowing gut transit may worsen invasive disease. This is an overlap with the original symptomatic indication, not a true repurposing opportunity.
- Gastroduodenitis: A 2026 case report described loperamide-induced respiratory depression in severe gastrointestinal inflammation, suggesting increased systemic exposure when the gut barrier is compromised.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
Currently no related literature available for acute contagious conjunctivitis.
For context, the literature found for other top-ranked predictions is summarised below (none supports efficacy):
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 17241255 | 2007 | Case report | J Travel Med | Fulminant amoebic colitis and toxic megacolon after heavy loperamide use (amoebic dysentery prediction) |
| 41924411 | 2026 | Case report | Cureus | Respiratory depression with loperamide in severe chemotherapy-related GI inflammation (gastroduodenitis prediction) |
| 3893119 | 1985 | Review | Am J Med | Non-fluid therapy and chemoprophylaxis of acute diarrhoea (amoebic dysentery prediction) |
Australia Market Information
| ARTG Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| 10592L | Gastrex | Capsule containing loperamide hydrochloride 2 mg | Not specified in the data compiled for this report |
Safety Considerations
- Contraindications (knowledge-graph derived, not label text): liver disease, gallbladder disease, paralytic ileus, intestinal obstruction, familial visceral myopathy, dysentery, diarrhoeal disease, infectious diarrhoeal disease, intestinal infectious disease.
- Drug Interactions: 100 interactions were identified. Examples rated Major: abiraterone, ranitidine, fosamprenavir, gemfibrozil. Examples rated Moderate: codeine, dihydrocodeine, tramadol (additive opioid or CNS effects), chlorpheniramine, cetirizine, acrivastine, ethanol, salbutamol, galantamine, gemifloxacin.
- Case-report safety signals: toxic megacolon in infectious colitis, and systemic opioid effects (respiratory depression) when the gut barrier is inflamed.
Please also refer to the TGA-approved Product Information (PI) for full warnings and contraindications.
Conclusion and Next Steps
Decision: Hold
Rationale: The prediction for acute contagious conjunctivitis rests on model score alone (L5), with no trials, no literature and no plausible mechanism. Loperamide is also an oral gut-acting agent with no ocular route or activity. The remaining top predictions are either similarly unsupported or carry safety concerns.
To proceed, the following is needed:
- Mechanism of action data and a credible mechanistic hypothesis for ocular disease
- Preclinical evidence of anti-infective or anti-inflammatory activity in the conjunctiva
- Route-of-administration feasibility assessment (no ocular formulation is available)
- TGA Product Information warnings and contraindications for formal safety screening
- Approved indication text for the ARTG entry
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.