Fusidic Acid
| Evidence Level: L4 | Predicted Indications: 10 |
Table of Contents
Fusidic Acid: From Bacterial Skin and Other Infections to Exposure Keratitis
One-Sentence Summary
Fusidic acid is an antibiotic that acts mainly against Gram-positive bacteria such as Staphylococcus aureus. It is listed for infections including acne, folliculitis, bronchitis and urinary tract infection. The TxGNN model predicts it may be effective for exposure keratitis, but there are currently 0 clinical trials and only 1 publication (a case series on ocular Tsukamurella infection that did not test fusidic acid), so the prediction is still at an early, hypothesis-only stage.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Not stated in the Singapore licence records. The knowledge graph lists urinary tract infection, bronchitis, acne, folliculitis, seborrheic dermatitis, bacterial pneumonia and others |
| Predicted New Indication | Exposure keratitis |
| TxGNN Prediction Score | 99.95% |
| Evidence Level | L4 |
| Singapore Market Status | ✓ Marketed |
| Number of Registrations | 19 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Fusidic acid inhibits bacterial protein synthesis by targeting elongation factor G (EF-G). It is strongly active against Gram-positive bacteria, especially Staphylococcus aureus. Detailed mechanism-of-action data were not available in the data compiled for this report, so the description above relies on general pharmacological knowledge.
Exposure keratitis is a disorder of the corneal surface caused by incomplete eyelid closure and drying. The damaged cornea can become secondarily infected. Because fusidic acid is already available as a 1% eye-drop product in Singapore (Fucithalmic), topical antistaphylococcal activity at the eye surface is plausible.
However, the only linked paper is a case series of ocular Tsukamurella infections, which did not study fusidic acid for this condition. The very high TxGNN score is a computational prediction, not clinical evidence. Any benefit would be limited to secondary bacterial infection, not the underlying dryness or exposure.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 31246677 | 2019 | Case series | Cornea | Largest case series of Tsukamurella-associated ophthalmic infections, covering clinical spectrum, risk factors, treatment and outcome, including a first report of ocular implant infection after enucleation. Fusidic acid was not tested. |
Singapore Market Information
The Singapore licence records contain no approved indication text. All 19 authorisations are valid single-ingredient products. The five main ones are listed below.
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| SIN00722P | Fucidin Ointment 2% | Ointment | Not stated in the records |
| SIN01547P | Fucidin Cream 2% | Cream | Not stated in the records |
| SIN00726P | Fucithalmic Eye Drops 1% | Solution | Not stated in the records |
| SIN10834P | Fucidin H Cream | Cream | Not stated in the records |
| SIN00723P | Fucicort Cream | Cream | Not stated in the records |
The remaining products include generic fusidic acid creams and ointments (e.g. Defuzin, Duzen, Balad, Disuf, Foban) and fusidic acid–corticosteroid combinations (e.g. Fucicort Lipid Cream, Fobancort, Defuzin-B).
Safety Considerations
- Disease-level cautions from the knowledge graph (not label text): The knowledge graph links fusidic acid to cautions in several conditions. These include liver failure and liver disease, kidney disease, gallbladder disease, herpes simplex virus keratitis, glaucoma and ocular hypertension, eye infectious disease and conjunctivitis, Clostridium difficile colitis and other colitis, diabetes and diabetic ketoacidosis, myasthenia gravis, and some cardiac conduction disorders. Several of these are relevant to ocular use (herpes simplex keratitis, glaucoma, ocular hypertension, eye infection). These links may partly reflect combination or systemic products and must be checked against the official label before any ophthalmic repurposing.
- Drug interactions: No interaction records were found.
For all other safety information, please refer to the package insert.
Conclusion and Next Steps
Decision: Hold
Rationale: The prediction rests on a high model score and a plausible antistaphylococcal mechanism, but there are no clinical trials and no literature testing fusidic acid in exposure keratitis. The only linked paper is unrelated to the drug. Eye-specific cautions in the knowledge graph and rising staphylococcal resistance add further uncertainty.
To proceed, the following is needed:
- Official package insert warnings and contraindications from the Health Sciences Authority (HSA), which are currently missing and block safety screening
- Detailed mechanism-of-action data from DrugBank
- Approved indication text for the Singapore licences, particularly the Fucithalmic eye drops
- Evidence that fusidic acid is effective and safe for secondary infection in exposure keratitis (for example, microbiology of infected cases, susceptibility data, and a clinical study)
- Review of local staphylococcal resistance to fusidic acid
- Review of the knowledge-graph ocular cautions (herpes simplex keratitis, glaucoma, conjunctivitis)
Other predicted indications: None of the other nine predictions has clinical trial support.
- Otitis externa (rank 3, L4) has only indirect microbiology and resistance papers, mostly canine, and is a research question rather than a candidate.
- The remaining eight are non-specific categories (e.g. non-human animal disease, post-infectious syndromes) or mechanistically implausible (e.g. Chagas cardiomyopathy, infection-related hemolytic uremic syndrome, where antibiotics are generally avoided). All are at L5 with a Hold recommendation.
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.