Ertapenem

Evidence Level: L5

Predicted Indications: 1

Ertapenem

Pharmacist Assessment Report

Ertapenem: Bacterial arthritis

One-Sentence Summary

Ertapenem is a broad-spectrum carbapenem antibiotic, originally used for bacterial pneumonia, streptococcal pneumonia, and Peptostreptococcus infections. The TxGNN model predicts it may be effective for bacterial arthritis, supported by no registered clinical trials and 10 publications, mostly case reports and cohort studies.

Quick Overview

Item	Content
Original Indication	Not recorded in the local data
Predicted New Indication	Bacterial arthritis
TxGNN Prediction Score	0.9972
Evidence Level	L5
Canada Market Status	Marketed (marketed DINs: 6 of 6)
Number of DINs	6 (marketed: 6)
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 general knowledge, ertapenem is a carbapenem that inhibits bacterial cell wall synthesis by binding penicillin-binding proteins. It is active against many Enterobacterales (including ESBL producers), streptococci, methicillin-susceptible staphylococci, and anaerobes.

These pathogens are commonly involved in septic arthritis and bone and joint infections. Ertapenem’s original indications (pneumonia, anaerobic infections) already overlap with this pathogen spectrum, so the prediction is an extension of use rather than a novel mechanism. Once-daily dosing also supports outpatient parenteral therapy.

The evidence is indirect, however. It consists of case reports and uncontrolled series, such as septic arthritis treated successfully with ertapenem, and a retrospective cohort of 306 outpatients on long-term ertapenem in which bone and joint infections were among the indications.

Clinical Trial Evidence

For bacterial arthritis (the top prediction), currently no related clinical trials are registered.

For the second prediction, Staphylococcus aureus infection:

Trial Number	Phase	Status	Enrollment	Key Findings
NCT07148960	Phase 4	Enrolling by invitation	300	Open-label randomized trial testing whether early dual IV antibiotic therapy shortens S. aureus bacteremia (<6 days) and improves outcomes versus single therapy. No results yet; the dual regimen needs confirmation against the protocol.
NCT04886284	Phase 2	Recruiting	60	Cefazolin plus ertapenem for MSSA bacteremia (CERT), a sub-study of the SNAP platform trial. No results yet; small sample.

Literature Evidence

Bacterial arthritis (top prediction)

PMID	Year	Type	Journal	Key Findings
24709258	2014	Cohort	Antimicrob Agents Chemother	Retrospective study of 306 outpatients on long-term ertapenem; indications included intra-abdominal infection (38%), pneumonia (12%), and bone and joint infection
31220276	2019	Cohort	J Antimicrob Chemother	Subcutaneous suppressive β-lactam therapy in 10 patients with bone and joint infections
39193962	2024	Cohort	Clin Lab	Pathogen distribution and antimicrobial resistance in bone and joint infections in young children
22233826	2011	Case report	J Chemother	Klebsiella pneumoniae septic wrist arthritis treated successfully with ertapenem and levofloxacin
31352398	2019	Case report	BMJ Case Rep	Citrobacter koseri osteomyelitis with septic arthritis in a diabetic foot, treated successfully with ertapenem
31585203	2020	Case report with review	Anaerobe	Clostridium paraputrificum septic arthritis and osteomyelitis of the shoulder
37578166	2023	Case report with review	J Investig Med High Impact Case Rep	Prevotella bivia septic arthritis in an immunocompetent adult
38924836	2024	In vitro study	Diagn Microbiol Infect Dis	Auranofin restores ertapenem susceptibility in carbapenem-resistant E. coli

Canada Market Information

DIN	Product Name	Dosage Form	Approved Indication
02247437	INVANZ	Not specified	Not specified
02492148	ERTAPENEM FOR INJECTION	Not specified	Not specified
02496127	ERTAPENEM FOR INJECTION	Not specified	Not specified
02490773	ERTAPENEM FOR INJECTION	Not specified	Not specified
02537176	ERTAPENEM FOR INJECTION	Not specified	Not specified

A sixth licence (DIN 02511150, ERTAPENEM FOR INJECTION) is also valid. All 6 licences are single-ingredient products in valid status.

Safety Considerations

Contraindication-related conditions (knowledge graph, not label text): epilepsy, kidney disease, pyoureter, Clostridium difficile colitis, and perinatal necrotizing enterocolitis. These come from a drug-disease relationship database and should be verified against the product labelling.
Drug Interactions: 38 interactions were identified. The only one rated Major is bupropion. Moderate interactions involve picosulfuric acid, polyethylene glycol (3350 with electrolytes), and sodium sulfate. The remaining listed interactions (e.g., vancomycin, metronidazole, morphine, metformin, omeprazole) have an unclassified severity level.
Please refer to the package insert for official warnings and contraindications.

Conclusion and Next Steps

Decision: Hold (for bacterial arthritis)

Rationale: The bacterial arthritis prediction has a high model score, but the supporting evidence is limited to case reports, small cohorts, and in vitro work, with no registered clinical trials. This corresponds to evidence level L4. The S. aureus infection prediction is more advanced (L2, with two ongoing trials of the cefazolin combination) and is better framed as a research question awaiting trial results.

To proceed, the following is needed:

Health Canada package insert warnings and contraindications, which are currently missing and block safety screening
Mechanism of action data from DrugBank
Approved indication text and dosage forms for the Canadian licences
Prospective or comparative studies of ertapenem in bone and joint infections
Results from NCT04886284 and NCT07148960 for the S. aureus combination indication
A dose and renal function plan, given the kidney disease and seizure-related flags and the Major bupropion interaction
Disclaimer

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