Cefazolin

證據等級: L5

預測適應症: 8 個

Cefazolin: From Bacterial Infections to Infectious Otitis Media

One-Sentence Summary

Cefazolin is a first-generation cephalosporin antibiotic, widely established for surgical prophylaxis and treatment of susceptible gram-positive bacterial infections. The TxGNN model predicts it may be effective for Infectious Otitis Media, with 1 clinical trial and 3 publications currently supporting this direction.

Quick Overview

Item	Content
Original Indication	No registration data available (known use: surgical prophylaxis, gram-positive bacterial infections)
Predicted New Indication	Infectious Otitis Media
TxGNN Prediction Score	99.44%
Evidence Level	L3
US Market Status	Not marketed (0 registered licenses)
Number of NDAs	0
Recommended Decision	Hold

Why is This Prediction Reasonable?

Detailed mechanism of action data is not available in this Evidence Pack. Based on known pharmacology, Cefazolin is a first-generation cephalosporin that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), resulting in bactericidal activity. Its primary spectrum covers gram-positive organisms — particularly Staphylococcus aureus and Streptococcus species — as well as limited gram-negative coverage.

Infectious otitis media (AOM) is predominantly caused by Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. Cefazolin addresses the gram-positive component effectively, but faces a critical spectrum gap: H. influenzae is intrinsically resistant to first-generation cephalosporins, and M. catarrhalis exhibits high β-lactamase production rates — together accounting for 25–40% of pediatric AOM cases. This mechanistic mismatch limits cefazolin’s utility as an empirical first-line agent.

Where cefazolin does show clinical relevance is in complicated AOM presentations. PMID 39567876 (2025) reports its use as part of a ceftazidime + cefazolin combination for Gradenigo Syndrome — a rare petrous apicitis complication of otitis media — where gram-positive coverage complements ceftazidime’s gram-negative spectrum. This represents a niche combinational role rather than a standalone indication.

Clinical Trial Evidence

Trial Number	Phase	Status	Enrollment	Key Findings
NCT01511107	Phase 2b	Terminated	520	Double-blind, placebo-controlled RCT in children aged 6–23 months comparing 5-day vs. 10-day antibiotic courses for AOM, aimed at assessing antimicrobial resistance reduction strategies. Trial was terminated prior to completion; root cause of termination (efficacy failure, safety signal, or recruitment difficulty) has not been disclosed and represents a key negative signal.

Literature Evidence

PMID	Year	Type	Journal	Key Findings
39567876	2025	Case Series	Annals of Otology, Rhinology & Laryngology	Ceftazidime + Cefazolin empiric combination for Gradenigo Syndrome (AOM-related petrous apicitis). Describes rationale for including cefazolin to cover Staphylococcus and Streptococcus in a complex otitis media complication.
877649	1977	Review	Southern Medical Journal	Review of cephalosporin use in pediatric practice; notes efficacy of cephalosporins against gram-positive cocci in pediatric infections including ear infections, with discussion of spectrum and safety profile.
3742953	1986	Case Series	Clinical Pharmacy	Stevens-Johnson syndrome case in a 2.5-year-old child treated with IV cefazolin (among other agents) for otitis media and upper airway infection. Documents incidental IV cefazolin use in a pediatric AOM context with subsequent adverse drug reaction workup.

US Market Information

No registered licenses or NDA records are available for Cefazolin in the current regulatory dataset (0 licenses). This likely reflects a data gap in the Evidence Pack rather than true non-availability, given cefazolin’s extensive parenteral use in US clinical practice. Regulatory data should be verified directly via the FDA Orange Book or DailyMed before drawing conclusions about market status.

Safety Considerations

Please refer to the package insert for safety information.

Conclusion and Next Steps

Decision: Hold

Rationale: Despite a high TxGNN prediction score (99.44%), the available clinical evidence is limited to a single terminated Phase 2b trial and three publications of moderate-to-low quality (case series, a 1977 review). More critically, cefazolin’s antimicrobial spectrum systematically misses the two most prevalent AOM pathogens (H. influenzae and M. catarrhalis), creating a fundamental mechanistic mismatch for empirical infectious otitis media treatment.

To proceed, the following is needed:

Termination root cause for NCT01511107 — if terminated for futility or a safety signal, this is a strong negative signal that should effectively close the infectious otitis media indication
Regulatory data verification — confirm US FDA approved indications via Orange Book/DailyMed, as 0-license status appears to be a data gap
Formal MOA data from DrugBank — complete the mechanistic link analysis with structured PBP-binding and spectrum data
Pathogen-stratified clinical evidence — data on cefazolin’s outcomes specifically in gram-positive AOM (e.g., MSSA-driven otitis media) to test whether a narrowed indication is viable
Package insert safety review — key warnings, contraindications, and drug interactions must be evaluated before any S1 safety screening can proceed
Reconsider the primary investigation target — Middle Ear Disease (rank 3, evidence level L2, “Proceed with Guardrails”) has stronger evidence for surgical prophylaxis in otologic procedures, which aligns better with cefazolin’s established clinical role and may represent a more productive repurposing direction
Disclaimer

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