Doxycycline
| Evidence Level: L4 | Predicted Indications: 10 |
Table of Contents
Doxycycline: From Bacterial Infections to Punctate Epithelial Keratoconjunctivitis
One-Sentence Summary
Doxycycline is a broad-spectrum tetracycline-class antibiotic; a specific licensed indication text is not present in this evidence pack, though its established use is in bacterial and rickettsial infections. The TxGNN model predicts possible efficacy for Punctate Epithelial Keratoconjunctivitis, but this direction is currently supported by only 1 publication and no registered clinical trials, making the evidence base very preliminary.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Not specified in the evidence pack (Doxycycline is a tetracycline-class antibiotic; no licensed indication text was returned for this record) |
| Predicted New Indication | Punctate Epithelial Keratoconjunctivitis |
| TxGNN Prediction Score | 99.94% (model rank 1056) |
| Evidence Level | L4 |
| UK Market Status | Not marketed |
| Number of Marketing Authorisations | 0 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data is not available. Based on known information, Doxycycline is part of the tetracycline antibiotic class, its efficacy in bacterial and rickettsial infections has been proven, and mechanistically it may be applicable to punctate epithelial keratoconjunctivitis.
Doxycycline’s anti-inflammatory and anti-matrix-metalloproteinase (anti-MMP) properties are already established in routine ocular surface therapy (e.g. dry eye disease and rosacea-associated blepharitis), which provides a plausible theoretical basis for extending its use to post-infectious corneal epithelial disease.
However, the sole supporting publication is a case description of persistent punctate epithelial keratitis following chlamydial follicular conjunctivitis, treated historically with oral tetracycline/doxycycline for the antecedent conjunctivitis rather than as a direct interventional treatment for the keratitis itself. The evidence is therefore indirect — it documents a disease sequence, not a therapeutic effect of doxycycline on this specific corneal condition.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 1424659 | 1992 | Case Report/Observational | Cornea | Describes two cases of chlamydial follicular conjunctivitis treated with oral tetracycline or doxycycline, in which recurrent bilateral punctate epithelial keratitis subsequently developed despite resolution of the follicular conjunctivitis; not a treatment-efficacy study of doxycycline for the keratitis itself |
Safety Considerations
Please refer to the SmPC and BNF for safety information. Report suspected adverse reactions via the Yellow Card Scheme.
Conclusion and Next Steps
Decision: Hold
Rationale: The only available evidence is a single case report describing disease progression rather than an interventional trial of doxycycline treating punctate epithelial keratoconjunctivitis. With no clinical trials, no MOA data, and no UK marketing authorisation on record for this candidate, the evidence base (L4) is insufficient to justify further investment at this time.
To proceed, the following is needed:
- Mechanism of action (MOA) data for Doxycycline (flagged as a High-severity data gap)
- UK/MHRA SmPC warnings, contraindications and interaction data (flagged as a Blocking data gap — required before any S1 safety screening)
- At least one prospective or interventional study assessing doxycycline specifically for post-infectious punctate epithelial keratoconjunctivitis
- Confirmation of current UK marketing authorisation status, since none is on record for this drug
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.