Ofloxacin

Evidence Level: L5

Predicted Indications: 10

Ofloxacin

Pharmacist Assessment Report

Ofloxacin: From Bacterial Infections to Polyclonal Hyperviscosity Syndrome

One-Sentence Summary

Ofloxacin is a fluoroquinolone antibacterial, originally used for infections such as typhoid fever, urinary tract infection, bronchitis and bacterial pneumonia. The TxGNN model predicts it may be effective for polyclonal hyperviscosity syndrome, but there are 0 clinical trials and 0 publications supporting this prediction. It is a model-only prediction with no mechanistic rationale.

Quick Overview

Item	Content
Original Indication	Typhoid fever, salmonellosis, urinary tract infection, bronchitis, bacterial pneumonia and other bacterial infections (the ARTG entry does not state an approved indication)
Predicted New Indication	Polyclonal hyperviscosity syndrome
TxGNN Prediction Score	0.9991
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. Ofloxacin is a fluoroquinolone, a class that inhibits bacterial DNA gyrase and topoisomerase IV, and its efficacy in bacterial infections is well established.

Polyclonal hyperviscosity syndrome is a plasma protein/immunoglobulin disorder, and there is no plausible link between antibacterial DNA gyrase inhibition and this condition. The high score from the TxGNN model (deep learning) may reflect similarities the model learned between related diseases, not biological evidence. This prediction is not considered reasonable on current evidence.

Other predictions reviewed

Nine other predictions were reviewed. Most are also model-only (L5) with no mechanistic link: hyperamylasemia, congenital analbuminemia, blood group incompatibility, premalignant haematological disease, monoclonal gammopathy, a haematological disease associated with acquired peripheral neuropathy, and congenital haematological disorder. For the neuropathy-related prediction, fluoroquinolones are themselves associated with peripheral neuropathy, which argues against use.

Two predictions have somewhat more substance:

Septicaemic plague (rank 8, L4): This is biologically plausible. Yersinia pestis is highly susceptible to ofloxacin in vitro, and mouse and primate models show benefit for prophylaxis and treatment. However, no human trials were identified, and this is better viewed as an extension of ofloxacin’s antibacterial spectrum than true repurposing.
Punctate epithelial keratoconjunctivitis (rank 10, L4): Ofloxacin is available as an ophthalmic antibacterial, so a loose link exists if a bacterial component is present. The only retrieved paper is a case report on a vernal shield ulcer healed by surgical debridement, which does not support ofloxacin efficacy. The condition is often viral or inflammatory.

Clinical Trial Evidence

Currently no related clinical trials registered.

Literature Evidence

For the top-ranked prediction (polyclonal hyperviscosity syndrome), currently no related literature available.

Literature for the other predictions is limited and indirect. The most relevant items are for septicaemic plague:

PMID	Year	Type	Journal	Key Findings
16127904	2002	Animal study	Antibiot Khimioter	Ofloxacin was effective in experimental plague prophylaxis and treatment in mice; efficacy was lower against strains lacking fraction I and mouse toxin
8203841	1994	Animal study	Antimicrob Agents Chemother	Ofloxacin and other antibiotics compared with streptomycin in a murine Y. pestis systemic infection model
9517950	1998	Animal study	Antimicrob Agents Chemother	Mouse model of pneumonic plague used to compare antibiotic treatments with streptomycin
11871319	2001	Animal study	Antibiot Khimioter	Primate model of bubonic plague developed to evaluate antibacterial efficacy
10987101	2000	Animal study	Antibiot Khimioter	Combined fluoroquinolone and specific plague prevention evaluated in mice; fluoroquinolones, including ofloxacin, interfered with post-vaccine immunity
8540736	1995	In vitro	Antimicrob Agents Chemother	Ofloxacin was highly active against 78 Y. pestis strains (ceftriaxone and ciprofloxacin most active)
8913481	1996	In vitro	Antimicrob Agents Chemother	Ofloxacin was highly active against 100 human Y. pestis isolates (MIC90 <0.03 µg/mL)
11858365	2002	Case report	Joint Bone Spine	S. lugdunensis discitis in a patient with multiple myeloma treated with ofloxacin and pristinamycin; unrelated to treating monoclonal gammopathy
16670489	2006	Case report	Cornea	Vernal shield ulcer healed after surgical debridement; does not establish ofloxacin efficacy

Australia Market Information

ARTG Number	Product Name	Dosage Form	Approved Indication
ARTG 5567B	Ocuflox	Eye drops 3 mg per mL, 5 mL	Not stated in the data compiled

The only listed product is an ophthalmic formulation. Its route is unlikely to suit a systemic condition such as polyclonal hyperviscosity syndrome.

Safety Considerations

Contraindications flagged in the knowledge graph (not label text)

The TxGNN knowledge graph links ofloxacin to many contraindicated conditions. The main groups are:

Cardiac: long QT syndrome (including familial), torsades de pointes
Neurological and neuromuscular: epilepsy, myasthenia gravis, peripheral neuropathy and other peripheral nervous system disease
Liver and kidney: liver failure, liver disease, drug-induced liver injury, kidney disease, impaired renal function
Musculoskeletal: tendinitis, periarthritis, rhabdomyolysis
Metabolic: diabetes mellitus, diabetic ketoacidosis, potassium deficiency
Haematological: thrombocytopenia, anaemia, leukopenia
Gastrointestinal: Clostridium difficile colitis

Drug Interactions

Interaction screening returned 100 interactions. Examples of those classed as Major are:

Corticosteroids: hydrocortisone, dexamethasone, betamethasone and triamcinolone
Bupropion
Chlorpropamide

Examples of those classed as Moderate include:

Antidiabetic agents: metformin, pioglitazone, acarbose, canagliflozin, alogliptin and albiglutide
Famotidine
Loperamide
Acetylsalicylic acid
Calcium and potassium salts

For ofloxacin, the corticosteroid combinations raise tendon-injury concerns, and the antidiabetic combinations raise concerns about blood glucose disturbance.

Please also refer to the TGA-approved Product Information (PI) for full warnings and contraindications.

Conclusion and Next Steps

Decision: Hold

Rationale: The top prediction is supported only by a score from the TxGNN model (deep learning), which may reflect similarities the model learned between related diseases, not biological evidence. There are no trials or literature, and no plausible mechanism links an antibacterial DNA gyrase inhibitor to a plasma protein disorder. The only locally registered product is an eye drop, and the safety profile includes numerous flagged contraindications.

To proceed, the following is needed:

Mechanism of action data and a credible biological rationale for polyclonal hyperviscosity syndrome
Any preclinical or clinical evidence for the predicted indication
The TGA Product Information, including warnings and contraindications, to support safety screening
If pursuing a more plausible direction, such as plague, a review of existing guidelines and human data, noting that this is an antibacterial spectrum extension and not true repurposing
Disclaimer

This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.