Roxithromycin
| Evidence Level: L4 | Predicted Indications: 10 |
Table of Contents
Roxithromycin: From Macrolide Antibacterial to Leprosy
One-Sentence Summary
Roxithromycin is a macrolide antibiotic that is registered and marketed in South Africa as an oral tablet. The TxGNN model predicts it may be useful for leprosy, but there are 0 clinical trials and only 5 publications, all reviews or laboratory and animal studies. The evidence is preclinical (L4), so this is a research question rather than a treatment recommendation.
Quick Overview
| Item | Content |
|---|---|
| Predicted New Indication | Leprosy |
| TxGNN Prediction Score | 99.70% |
| Evidence Level | L4 |
| South Africa Market Status | Marketed |
| Number of SAHPRA Registrations | 1 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data for roxithromycin is not available in the evidence pack. Macrolides as a class inhibit bacterial protein synthesis by binding the 50S ribosomal subunit. Leprosy is caused by Mycobacterium leprae, so an antibacterial link is plausible.
The supplied literature supports this link only at the class level. In a mouse footpad study, roxithromycin and clarithromycin were both consistently active and bactericidal against M. leprae, while erythromycin and azithromycin were inactive. Clarithromycin was the stronger of the two, possibly because it reaches higher levels at the site of infection. A Japanese review also notes anti-M. leprae activity for roxithromycin, plus anti-inflammatory and immunomodulatory effects that may matter in leprous neuropathy.
Because the mouse data show that activity differs between macrolides, results cannot simply be carried over from one macrolide to another. No human data were supplied.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 12762831 | 2003 | Review | Am J Clin Dermatol | Guide to macrolide use in skin infections; class-level overview and adverse effect and interaction considerations |
| 10481449 | 1999 | Review | Nihon Hansenbyo Gakkai Zasshi | Roxithromycin, clarithromycin, minocycline and fosfomycin show anti-M. leprae activity plus anti-inflammatory and immunomodulatory effects, in the context of leprous neuropathy |
| 1648889 | 1991 | Preclinical (mouse) | Antimicrob Agents Chemother | In mouse footpads, roxithromycin and clarithromycin were active and bactericidal against M. leprae; erythromycin and azithromycin were inactive; clarithromycin was superior |
| 2665640 | 1989 | Preclinical (in vitro) | Antimicrob Agents Chemother | Macrophage-based rapid screen of over 25 antimicrobial agents for antileprosy potential |
| 3072920 | 1988 | Preclinical (in vitro and animal) | Antimicrob Agents Chemother | Compared newer macrolides against M. leprae in vitro and in mice |
South Africa Market Information
| Registration Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| Reg. No. 35/20.1.1/0267 | Roxulide | Tablet | Not listed in the supplied registration data |
Safety Considerations
Please refer to the SAHPRA-approved Professional Information (PI) for safety information. Report adverse drug reactions to SAHPRA.
The interaction query in the evidence pack returned no results, which does not mean there are no interactions. One in vitro study (PMID 37971309) found that macrolide and ketolide antibiotics reduced the cytotoxic effect of trastuzumab emtansine in HER2-positive breast cancer cells. This is a preclinical signal only, but it should be checked if roxithromycin is ever considered in patients receiving that therapy.
Conclusion and Next Steps
Decision: Hold
Rationale: The leprosy prediction is biologically plausible and has some in vitro and mouse support. However, there are no human trials, the evidence is class-level, and clarithromycin outperformed roxithromycin in the animal model. The other nine predicted indications in the pack are also on Hold, with no trials and little or no relevant literature.
To proceed, the following is needed:
- The SAHPRA package insert, including warnings, contraindications and the approved indication (currently a blocking gap for safety screening)
- Mechanism of action data from DrugBank
- Roxithromycin-specific efficacy data against M. leprae, and a comparison with clarithromycin and current standard leprosy regimens
- Any human clinical data, including trial registrations in ClinicalTrials.gov, SANCTR or PACTR
- A drug interaction check once the package insert is available
This report is for research reference only and does not constitute medical advice. Repurposing candidates require clinical validation before any use.
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.