Tobramycin
| 證據等級: L5 | 預測適應症: 10 個 |
目錄
Tobramycin: From Bacterial Infection to Exposure Keratitis
One-Sentence Summary
Tobramycin is an aminoglycoside antibiotic generally used against gram-negative bacterial infections (notably Pseudomonas aeruginosa); it is not currently marketed in New Zealand and no approved-indication text is on file for this drug. The TxGNN model predicts it may be effective for Exposure Keratitis, with a prediction score of 99.93%, but this is currently supported only by 2 clinical trials of low direct relevance and 7 mostly case-report-level publications.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Not available — drug is not marketed in New Zealand (no license/indication text on file); generally known as an antibacterial for gram-negative infections |
| Predicted New Indication | Exposure keratitis |
| TxGNN Prediction Score | 99.93% |
| Evidence Level | L4 |
| New Zealand Market Status | Not Marketed |
| Number of Authorizations | 0 |
| Recommended Decision | Research Question |
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data is not available for tobramycin in this evidence pack. Based on known pharmacology, tobramycin is an aminoglycoside antibiotic with strong bactericidal activity against common gram-negative and some gram-positive organisms (e.g., Pseudomonas aeruginosa, Staphylococcus aureus), and its efficacy against bacterial ocular pathogens is well established in topical ophthalmic use.
Exposure keratitis results from incomplete eyelid closure, leading to corneal drying and epithelial breakdown; it is not itself an infectious disease. The rationale connecting the two is therefore indirect: when exposure keratitis becomes complicated by secondary bacterial infection, topical antibiotic coverage — including tobramycin — may be clinically warranted. However, tobramycin's mechanism addresses only the secondary infection, not the underlying mechanical/neurological cause of eyelid closure failure, so it cannot treat the primary disease process. This distinguishes the prediction as plausible for a complication of the disease rather than the disease itself.
Clinical Trial Evidence
| Trial Number | Phase | Status | Enrollment | Key Findings |
|---|---|---|---|---|
| NCT06200727 | N/A | Unknown | 170 | Evaluates platelet-rich fibrin (PRF) membrane across four ophthalmic conditions (macular hole, pterygium, corneal ulcer, post-trabeculectomy); not specific to tobramycin or exposure keratitis (relevance grade C). |
| NCT05313828 | N/A | Unknown | 40 | Compares treatment modalities for dendritic viral (HSV) corneal ulcer; targets viral, not bacterial exposure, keratitis (relevance grade C). |
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 34987857 | 2021 | Case report | Oxford Medical Case Reports | Bacterial keratitis from multi-drug-resistant Shewanella algae in a bedridden patient unable to close his eyes voluntarily — an exposure-related mechanism. |
| 2707046 | 1989 | In vitro toxicity study | Current Eye Research | Compares corneal epithelial cytotoxicity of neomycin, gentamicin, tobramycin, and amikacin in a rabbit model. |
| 17228760 | 2006 | In vitro susceptibility comparison | Nippon Ganka Gakkai Zasshi | MIC and postantibiotic effect of antibiotic eyedrops against infectious keratitis isolates in Japan. |
| 11581057 | 2001 | Case report | Ophthalmology | First reported case of contact-lens-related Bacillus cereus keratitis and ulcer. |
| 12861116 | 2003 | Case report | Eye & Contact Lens | Bilateral MRSA keratitis following photorefractive keratectomy. |
| 33847093 | 2021 | Pending classification | Polish Journal of Veterinary Sciences | Seroprevalence and treatment outcomes of feline ocular toxoplasmosis (60 cases) — veterinary, not directly relevant. |
| 14574976 | 2003 | Pending classification | Yan Ke Xue Bao | Case report of paracentral corneal dellen in Graves ophthalmopathy — not an infection/antibiotic study. |
New Zealand Market Information
Tobramycin currently has no product authorizations on record in New Zealand (market status: Not Marketed; 0 licenses).
Safety Considerations
Please refer to the package insert for safety information.
Conclusion and Next Steps
Decision: Research Question
Rationale: The mechanistic link is plausible only for secondary bacterial infection in exposure keratitis, not the primary condition, and current evidence consists of 2 low-relevance trials and mostly case-report/in-vitro literature (Evidence Level L4). Two blocking/high-severity data gaps — missing TFDA/package-insert safety data (DG001, blocking) and missing mechanism-of-action data (DG002) — prevent progression past an initial safety screen.
To proceed, the following is needed:
- TFDA/regulatory package insert with warnings and contraindications (resolves DG001, currently blocking)
- Confirmed mechanism-of-action data from DrugBank or equivalent (resolves DG002)
- Dedicated clinical evidence on tobramycin specifically for bacterial-complicated exposure keratitis, rather than extrapolated from unrelated ophthalmic or viral keratitis studies
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.