Roxithromycin
| Evidence Level: L3 | Predicted Indications: 10 |
Table of Contents
Roxithromycin: From Bacterial Infections to Leprosy
One-Sentence Summary
Roxithromycin is a macrolide antibiotic, used for respiratory tract, urinary and soft tissue infections. The TxGNN model predicts it may be effective for leprosy, but there are currently no registered clinical trials and only 5 publications, mostly preclinical (in vitro and mouse studies) or reviews.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Not stated in the Singapore licence record (pharmacology sources describe respiratory tract, urinary and soft tissue infections) |
| Predicted New Indication | Leprosy |
| TxGNN Prediction Score | 99.70% |
| Evidence Level | L3 |
| Singapore Market Status | ✓ Marketed |
| Number of Registrations | 1 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Roxithromycin is a macrolide antibiotic. Macrolides inhibit bacterial protein synthesis by binding to the 50S ribosomal subunit. Detailed mechanism of action data is not otherwise available in the data compiled for this report. Its in vitro antibacterial activity is similar to erythromycin, mainly against Gram-positive bacteria and some Gram-negative bacteria such as Legionella pneumophila.
Leprosy is caused by Mycobacterium leprae, so an antibacterial agent is a biologically sensible candidate. Mouse footpad studies (1991) found roxithromycin and clarithromycin consistently active and bactericidal against M. leprae, while erythromycin and azithromycin were inactive. Clarithromycin was superior to roxithromycin, partly because of higher drug levels at the infection site. A Japanese review (1999) also notes anti-inflammatory and immunomodulatory effects of roxithromycin, which could matter for leprosy-related nerve inflammation.
The plausibility is therefore good, but roxithromycin appears less potent than clarithromycin, which is already the macrolide used in leprosy regimens. No roxithromycin-specific human data is available.
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 selecting and using macrolides in skin infections, including adverse effects and drug interactions |
| 10481449 | 1999 | Review | Nihon Hansenbyo Gakkai Zasshi | Clarithromycin, roxithromycin and others show anti-inflammatory and immunomodulatory action alongside anti-M. leprae activity; relevant to leprous neuropathy |
| 1648889 | 1991 | Animal study (mouse) | Antimicrob Agents Chemother | Roxithromycin and clarithromycin were bactericidal against M. leprae in mouse footpads; clarithromycin was superior |
| 2665640 | 1989 | In vitro | Antimicrob Agents Chemother | Over 25 antimicrobials screened for antileprosy potential in mouse macrophages |
| 3072920 | 1988 | In vitro/animal | Antimicrob Agents Chemother | Relative in vitro activities of newer macrolides against M. leprae compared |
Singapore Market Information
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| SIN11413P | UPLORES CAPSULE 150 mg | Capsule | Not stated in the licence record |
Safety Considerations
- Drug Interactions: Pharmacology data lists the motilin receptor (MLNR) as a target of roxithromycin, consistent with the prokinetic activity of macrolides. A 2023 in vitro study also found that macrolides and ketolides inhibited the cytotoxic effect of trastuzumab emtansine in HER2-positive breast cancer cells, suggesting a potential drug-antibody-drug conjugate interaction that deserves caution.
Please refer to the package insert for other safety information, including warnings and contraindications.
Conclusion and Next Steps
Decision: Hold
Rationale: The leprosy prediction is biologically plausible and supported by preclinical studies (in vitro and mouse). However, there are no clinical trials or human data for roxithromycin, and clarithromycin was more active and is already used in leprosy regimens. Evidence is insufficient to advance this as a treatment candidate, so it is best treated as a research question.
To proceed, the following is needed:
- Singapore package insert warnings and contraindications (a blocking gap for safety screening)
- Detailed mechanism of action data from DrugBank
- Roxithromycin-specific clinical or comparative data against clarithromycin in leprosy
- Evaluation of whether roxithromycin adds value over existing leprosy regimens
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.