Cephalexin
| Evidence Level: L4 | Predicted Indications: 10 |
Table of Contents
Cephalexin: From Bacterial Infections (Including Otitis Media) to Chronic Otitis Media
One-Sentence Summary
Cephalexin is a first-generation cephalosporin antibiotic, originally used for bacterial infections such as otitis media, streptococcal and staphylococcal infections, streptococcal pneumonia, bacterial arthritis and prostatitis. The TxGNN model predicts it may be effective for chronic otitis media, but there are no registered clinical trials and only 8 publications, mostly bacteriology surveys and reviews, with no direct trial of cephalexin in the chronic form. This is largely an extension of an existing use rather than true repurposing.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Infectious otitis media, streptococcal and staphylococcal infections, streptococcal pneumonia, bacterial arthritis, prostatitis (from the knowledge graph; the Singapore licence records contain no indication text) |
| Predicted New Indication | Chronic otitis media |
| TxGNN Prediction Score | 98.55% |
| Evidence Level | L4 |
| Singapore Market Status | ✓ Marketed |
| Number of Registrations | 11 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Detailed mechanism of action data is not available in the data compiled for this report. Based on known information, cephalexin is a first-generation cephalosporin that inhibits bacterial cell wall synthesis. Its efficacy in bacterial otitis media, a labelled use, is established, so an antibacterial link to chronic otitis media is plausible.
There are important limits. Chronic suppurative otitis media often involves Pseudomonas aeruginosa and anaerobes, which cephalexin covers poorly. The available literature is mostly bacteriology, susceptibility surveys, and reviews of other antibiotics. The disease is also closely related to the existing otitis media indication, so the high model score partly reflects ontology proximity rather than new biology.
Other predicted indications were also reviewed. Suppurative otitis media (98.53%) and middle ear disease (98.52%) have older comparative trials (L3), but these cover acute disease and the categories overlap with the existing label. The remaining predictions (otosalpingitis, non-suppurative and allergic otitis media, cholesterol granuloma, hyperamylasemia, polyclonal hyperviscosity syndrome, congenital analbuminemia) have no evidence and no plausible mechanism, and are likely model artifacts.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 6361325 | 1983 | RCT (double-blind) | Jpn J Antibiot | Cefroxadine vs cephalexin in acute suppurative otitis media and acute exacerbation of chronic suppurative otitis media; the two drugs gave almost equal outcomes in acute disease |
| 6798820 | 1981 | Microbiology study | Acta Otolaryngol | In chronic otitis media, cephalexin ear drops reduced bacterial counts in otorrhea more than oral cephalexin |
| 22737435 | 2011 | Cross-sectional susceptibility study | Iran Red Crescent Med J | Bacteria isolated from chronic suppurative otitis media and their antibiotic susceptibility |
| 12017394 | 2002 | Review | Clin Ther | Review of cefdinir, another cephalosporin, in otitis media and other infections (not cephalexin) |
| 11838568 | 2001 | Review | Indian J Pediatr | Upper respiratory tract infections, including otitis media; most are viral |
| 1920724 | 1991 | Microbiology study | JAMA | Bacteriology of acute otitis media in adults |
| 3581497 | 1987 | Cohort | Clin Otolaryngol | Persistent middle ear effusions in children with recurrent acute otitis media |
| 3063494 | 1988 | Review | Drugs | Review of enoxacin (a different antibiotic) |
Singapore Market Information
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| SIN08381P | APO-CEPHALEX TABLET 500 mg | Film-coated tablet | Not stated in records |
| SIN08382P | APO-CEPHALEX TABLET 250 mg | Film-coated tablet | Not stated in records |
| SIN11397P | CEFALEXIN CAPSULE 250 mg | Capsule | Not stated in records |
| SIN11396P | CEFALEXIN CAPSULE 500 mg | Capsule | Not stated in records |
| SIN10419P | SOFILEX FOR ORAL SUSPENSION 125 mg/5 ml | Powder for suspension | Not stated in records |
Five of 11 valid single-ingredient registrations are shown. All are currently valid and none are cancelled.
Safety Considerations
- Contraindications / disease associations (knowledge graph, not label text): kidney disease, pyoureter, Clostridium difficile colitis, perinatal necrotizing enterocolitis, colitis.
- Drug Interactions: 100 interactions were found. Those graded Moderate are metformin, balsalazide and picosulfuric acid. Others in the list, such as pantoprazole, omeprazole, cimetidine, vancomycin, doxycycline and morphine, have no assigned severity level.
Please refer to the package insert for label warnings and contraindications.
Conclusion and Next Steps
Decision: Hold
Rationale: Chronic otitis media has no registered trials and no direct cephalexin trial in the chronic form. The literature is mainly bacteriology and reviews of other drugs, and cephalexin has limited coverage of the Gram-negative organisms that dominate chronic suppurative disease. The indication also largely overlaps with the existing otitis media use.
To proceed, the following is needed:
- Package insert warnings and contraindications from the HSA (currently missing and blocking safety screening)
- Mechanism of action data from DrugBank
- Approved indication text for the Singapore licences
- Current susceptibility data for chronic otitis media pathogens, especially Pseudomonas aeruginosa and anaerobes
- A direct comparative study of cephalexin in chronic otitis media, or confirmation that the existing label already covers the intended use
- Consideration of suppurative otitis media as an alternative research question (L3, acute-disease evidence only)
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.