Cefoxitin

證據等級: L5

預測適應症: 10 個

Cefoxitin: From Broad-Spectrum Antibiotic to Infectious Otitis Media

One-Sentence Summary

Cefoxitin is a cephamycin (second-generation cephalosporin) antibiotic with broad-spectrum activity against gram-negative bacteria and anaerobes, historically used for surgical prophylaxis and treatment of serious bacterial infections, though it currently holds no marketing authorization in Canada. The TxGNN model’s top prediction is Infectious Otitis Media (score 99.30%), supported only by 2 peripheral literature references with no dedicated clinical trials; however, this is a multi-indication Evidence Pack where Urinary Tract Infection (4 clinical trials, 20 publications) and Gonococcal Urethritis (20 publications, multiple historical controlled trials) carry substantially stronger evidence. Across all 10 predicted indications, the most actionable repurposing signal is Gonococcal Urethritis (Evidence Level L2, “Proceed with Guardrails”), while the majority of otitis media predictions remain at the hypothesis stage.

Quick Overview

Item	Content
Original Indication	Not marketed in Canada — no approved indication on record
Predicted New Indication	Infectious Otitis Media
TxGNN Prediction Score	99.30%
Evidence Level	L4
Canada Market Status	✗ Not Marketed
Number of DINs	0
Recommended Decision	Hold (Research Question)

Why is This Prediction Reasonable?

Currently, formal mechanism of action data is not available in this Evidence Pack. Based on known pharmacological information, cefoxitin is a cephamycin antibiotic that inhibits bacterial cell wall synthesis by covalently binding to penicillin-binding proteins (PBPs). Its cephamycin core confers resistance to hydrolysis by many plasmid-mediated β-lactamases, providing clinically useful activity against gram-negative bacilli (including some ESBL-producing strains) and anaerobes — a spectrum broader than first-generation cephalosporins.

For infectious otitis media specifically, the predominant causative pathogens are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. Cefoxitin’s coverage of these organisms is limited compared to preferred agents such as amoxicillin-clavulanate, and its IV-only formulation makes it unsuitable for the outpatient setting where most otitis media is managed. The two available literature references address MRSA epidemiology (where cefoxitin functions as a disk-diffusion surrogate marker for oxacillin resistance, not as a treatment agent) and a rare case of Mycobacterium fortuitum otitis media — both peripheral to typical disease management. The mechanistic basis for this specific prediction is therefore narrow.

The TxGNN model has predicted a cluster of otitis media-related indications (ranks 1, 3, 4, 5, 9, 10) alongside urinary tract and urethral infections, suggesting the model is capturing cefoxitin’s broad antibacterial spectrum rather than any ear-specific pharmacology. The biologically strongest predictions are the UTI-related indications (cefoxitin’s documented anti-ESBL E. coli activity, confirmed in murine models) and gonococcal urethritis (demonstrated in multiple historical controlled clinical trials as an effective alternative to penicillin against penicillinase-producing Neisseria gonorrhoeae).

Clinical Trial Evidence

Currently no related clinical trials registered for Infectious Otitis Media.

Literature Evidence

PMID	Year	Type	Journal	Key Findings
33061472	2020	Review	Infection and Drug Resistance	MRSA as a cause of otitis media among other severe infections; cefoxitin cited as a surrogate disk-diffusion marker for MRSA identification, not as therapeutic agent
8783722	1996	Case Report + Case Series Review	Clinical Infectious Diseases	Mycobacterium fortuitum as a rare cause of otitis media and mastoiditis; amikacin-resistant isolate reported — cefoxitin is not a first-line or recommended treatment for NTM infections

Supplementary Evidence: Urinary Tract Infection (Rank #2)

TxGNN Score: 99.26% Evidence Level: L3 Recommendation: Research Question

Cefoxitin’s anti-ESBL E. coli activity makes urinary tract infection (particularly complicated UTI and acute pyelonephritis) the most scientifically plausible indication in this pack. Two dedicated Phase 4 RCTs were designed to test this hypothesis but both terminated early due to recruitment challenges, leaving the field without conclusive clinical data.

Clinical Trials — Urinary Tract Infection

Trial Number	Phase	Status	Enrollment	Key Findings
NCT01820793	N/A	TERMINATED	9	Directly studied cefoxitin PK/PD in acute pyelonephritis caused by CTX-M-type ESBL-producing E. coli; terminated due to recruitment difficulties — no efficacy conclusions possible
NCT02474706	Phase 4	TERMINATED	6	Non-inferiority RCT: cefoxitin vs. imipenem/cilastatin for ESBL-producing E. coli UTI; terminated after enrolling only 6 patients — entirely underpowered
NCT02959957	Phase 4	COMPLETED	157	RCT comparing temocillin vs. cefotaxime for febrile UTI; primary endpoint was intestinal microbiota collateral damage, not cefoxitin efficacy — provides indirect ecological safety context only
NCT01426191	N/A	COMPLETED	2032	Study of cefotaxime/sulbactam (not cefoxitin) for respiratory and UTI — low relevance

Key Literature — Urinary Tract Infection

PMID	Year	Type	Journal	Key Findings
22214774	2012	Animal Model	Antimicrobial Agents and Chemotherapy	Cefoxitin equivalent to carbapenems in murine UTI model caused by CTX-M-15 ESBL-producing E. coli CFT073 — proof-of-concept for biological plausibility
357399	1978	Clinical Study	J Antimicrobial Chemotherapy	Early clinical report of cefoxitin sodium in complicated UTI
4046178	1985	Clinical Trial	Japanese Journal of Antibiotics	Cefoxitin evaluated in 46 patients for prevention and treatment of postoperative UTI and pulmonary infections; generally favorable results
400934	1979	Clinical Study	Reviews of Infectious Diseases	Intramuscular cefoxitin in 102 patients with mild-to-moderate infections; UTI among indications included
40165096	2025	Retrospective Cohort	BMC Infectious Diseases	Cefepime vs. carbapenem for complicated UTI caused by cefoxitin-nonsusceptible ESCPM organisms; uses cefoxitin disk result as AmpC phenotyping surrogate
37284390	2023	Observational	Cureus	MDR-UTI in chronic kidney disease patients; cefoxitin included in susceptibility profiling panel
40057723	2025	Cross-sectional	BMC Microbiology	Uropathogen antimicrobial susceptibility and risk factors in Ethiopia; regional surveillance data
34659966	2021	Cross-sectional	Cureus	Frequency and resistance patterns of UTI-causing bacteria in Turkey; cefoxitin susceptibility data included
22749057	2012	Surveillance	International Journal of Antimicrobial Agents	SMART Asia-Pacific UTI Gram-negative surveillance (2009–2010); cefoxitin MIC data across 11 countries
7004691	1980	Review	Clinical Obstetrics and Gynecology	Review of puerperal infections including UTI; cefoxitin discussed as an option for polymicrobial infections

Supplementary Evidence: Gonococcal Urethritis (Rank #6)

TxGNN Score: 99.09% Evidence Level: L2 Recommendation: Proceed with Guardrails

No contemporary registered clinical trials were found. However, the 1970s–1980s literature contains multiple controlled clinical trials demonstrating that cefoxitin was an effective alternative to penicillin for gonorrhea treatment, particularly against penicillinase-producing Neisseria gonorrhoeae (PPNG). This represents the most robust historical clinical evidence in the entire Evidence Pack.

Key Literature — Gonococcal Urethritis

PMID	Year	Type	Journal	Key Findings
400933	1979	Controlled Clinical Trial	Reviews of Infectious Diseases	143 men with uncomplicated gonococcal urethritis; cefoxitin 2g IM + probenecid 1g vs. penicillin G — cefoxitin failure rate 1.8% vs. 3.6% (penicillin); effective against both PPNG and non-PPNG strains
111119	1979	Controlled Clinical Trial	New England Journal of Medicine	107 men in region with 40% PPNG prevalence; single-dose cefoxitin vs. procaine penicillin G — cefoxitin effective against penicillinase-resistant strains where penicillin failed
6658629	1983	RCT	Sexually Transmitted Diseases	406 men and women; cefoxitin 2g vs. penicillin G — no statistically significant difference in failure rate (5.1% vs. 4.3%); active in PPNG and proctitis
6303490	1983	Controlled Clinical Trial	British Journal of Venereal Diseases	128 men with culture-confirmed PPNG urethritis; cefoxitin 2g IM vs. ceftriaxone 250mg IM — both effective; ceftriaxone showed slightly superior cure rate
6228024	1983	Clinical Study	Sexually Transmitted Diseases	Cefoxitin 1g IM + probenecid 1g: 86/89 (97%) cure rate; 60% of infections caused by penicillin-resistant strains
3089907	1986	Clinical Study	Genitourinary Medicine	136 patients; cefoxitin 1g overall 96% cure rate for PPNG and non-PPNG strains; post-gonococcal urethritis rate noted
119328	1979	Clinical Trial	Sexually Transmitted Diseases	25 patients (10 men, 15 women); cefoxitin 1g and 2g IM against PPNG strains — both doses effective
3319500	1987	Review	Drugs	Comprehensive review of cephalosporins in gonorrhea; cefoxitin specifically identified as active for penicillin-resistant strains including PPNG
6234346	1984	Case Report	Journal of the American Optometric Association	Gonococcal conjunctivitis caused by PPNG treated successfully with cefoxitin 2g IM + probenecid 1g single dose
3929408	1985	Case Report	Sexually Transmitted Diseases	PPNG conjunctivitis in a 21-year-old man; single dose cefoxitin 2g IM + probenecid 1g resulted in satisfactory outcome

Summary of All Predicted Indications

Rank	Indication	TxGNN Score	Evidence Level	Recommendation	Assessment
1	Infectious Otitis Media	99.30%	L4	Hold	Narrow mechanistic link; cefoxitin covers few typical pathogens; MRSA/NTM angle only
2	Urinary Tract Infection	99.26%	L3	Research Question	2 terminated Phase 4 RCTs + animal model support; ESBL-UTI niche is biologically plausible
3	Chronic Otitis Media	99.12%	L4	Research Question	Anaerobic coverage relevant; no direct cefoxitin-specific clinical data
4	Suppurative Otitis Media	99.11%	L4	Research Question	Cefoxitin acts as MRSA surrogate test marker — diagnostic role, not therapeutic
5	Middle Ear Disease	99.11%	L3	Hold	One 1982 unregistered case series for cholesteatoma surgery prophylaxis; insufficient evidence
6	Gonococcal Urethritis	99.09%	L2	Proceed with Guardrails	Strongest evidence; multiple 1979–1986 controlled trials; contemporary susceptibility data needed
7	Ureaplasma Urethritis	99.09%	L5	Hold	Biological contradiction — β-lactams have no activity against cell wall-deficient Ureaplasma
8	Toxocariasis	99.09%	L5	Hold	Biological contradiction — cefoxitin is an antibacterial; no antiparasitic activity against nematodes
9	Otosalpingitis	99.08%	L5	Hold	No evidence; theoretical partial coverage only
10	Non-Suppurative Otitis Media	99.07%	L5	Hold	Primarily non-bacterial (eustachian tube dysfunction, allergy, viral); antibiotics not indicated per guidelines

Safety Considerations

Please refer to the package insert for safety information.

Note: Two data gaps were flagged in this Evidence Pack. DG001 (Blocking): TFDA package insert warnings and contraindications are unavailable — required before formal safety screening. DG002 (High): Formal MOA data is absent — impacts mechanistic analysis quality.

Conclusion and Next Steps

Decision: Hold (Primary prediction: Infectious Otitis Media, L4) Decision: Proceed with Guardrails (Strongest signal: Gonococcal Urethritis, L2)

Rationale:

The top-ranked TxGNN prediction (infectious otitis media) is not supported by meaningful clinical evidence and lacks a compelling mechanistic basis given cefoxitin’s limited coverage of typical otitis media pathogens. A “Hold” decision is appropriate for this and the other five otitis media-cluster predictions (ranks 1, 3, 4, 5, 9, 10), as these require at minimum prospective in vitro susceptibility data against local pathogen populations before further clinical consideration.

The most actionable finding is gonococcal urethritis: multiple controlled clinical trials from 1979–1986 established cefoxitin as an effective single-dose treatment for uncomplicated gonorrhea, including against penicillinase-producing strains. The primary caveat is that these data are 35–45 years old and predate modern fluoroquinolone resistance patterns in N. gonorrhoeae. Cefoxitin is not featured in current CDC or WHO gonorrhea treatment guidelines, representing a gap to be addressed before clinical use.

To proceed, the following is needed:

Immediate (blocking): Obtain TFDA package insert PDF and extract warnings, contraindications, and dosing information (DG001)
High priority: Confirm formal MOA via DrugBank API (DG002)
For Gonococcal Urethritis (Proceed with Guardrails):
- Obtain contemporary N. gonorrhoeae cefoxitin MIC surveillance data from target region
- Assess whether a cefoxitin-based regimen offers advantages over current guideline-recommended cephalosporins (e.g., ceftriaxone)
- Evaluate whether the historical dosing regimen (2g IM + probenecid 1g) remains appropriate given modern PK/PD standards
For Urinary Tract Infection (Research Question):
- Review reasons for early termination of NCT01820793 and NCT02474706 to inform feasibility of a new study design
- Conduct a prospective PK/PD study in ESBL-UTI patients with a revised and powered protocol
- Address IV-only formulation limitation — cefoxitin’s lack of oral bioavailability restricts outpatient UTI management utility
For all otitis media predictions:
- Collect in vitro susceptibility data for cefoxitin against regional middle ear pathogen isolates before investing further resources
  Disclaimer

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