What is a suitable oral antibiotic substitute for ertapenem (Invanz) for outpatient use?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: April 28, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

Ertapenem-equivalent oral antibiotics for outpatient use include high-dose amoxicillin-clavulanate (875/125 mg twice daily or 2000/125 mg twice daily extended-release) or fluoroquinolones (such as ciprofloxacin 500-750 mg twice daily or levofloxacin 750 mg daily). The choice of antibiotic depends on the specific infection, suspected pathogens, and local resistance patterns 1. Ertapenem is a broad-spectrum carbapenem antibiotic that covers many gram-positive, gram-negative, and anaerobic bacteria, so oral substitutes should be selected based on similar coverage needs.

  • Key considerations for selecting an oral antibiotic equivalent to ertapenem include:
    • Coverage of enteric gram-negative aerobic and facultative bacilli and enteric gram-positive streptococci
    • Coverage of obligate anaerobic bacilli for distal small bowel, appendiceal, and colon-derived infections
    • Local resistance patterns and susceptibility of common pathogens to the selected antibiotic
  • Patients should complete the full prescribed course (typically 7-14 days depending on the infection) and be monitored for clinical improvement.
  • If symptoms worsen or don't improve within 48-72 hours, reevaluation is necessary as parenteral therapy may be required.
  • Antibiotic selection should always consider patient allergies, comorbidities, and potential drug interactions 1.
  • For more resistant infections, combination therapy with trimethoprim-sulfamethoxazole (1-2 double-strength tablets twice daily) plus metronidazole (500 mg three times daily) may be appropriate 1.

From the FDA Drug Label

The clinical success rates at 10 to 21 days posttherapy (test-of-cure) were 83.9% (141/168) for ertapenem and 85. 3% (145/170) for piperacillin/tazobactam. Both regimens allowed the option to switch to oral amoxicillin/clavulanate for a total of 5 to 28 days of treatment (parenteral and oral). Both regimens allowed the option to switch to oral ciprofloxacin (500 mg twice daily) for a total of 10 to 14 days of treatment (parenteral and oral). Both regimens allowed the option to switch to oral amoxicillin/clavulanate for a total of 10 to 14 days of treatment (parenteral and oral).

Oral antibiotic substitutes for ertapenem may include:

  • Amoxicillin/clavulanate: as it was used as an oral option in some of the clinical trials
  • Ciprofloxacin: as it was used as an oral option in some of the clinical trials However, the choice of antibiotic should be based on the specific infection being treated and the susceptibility of the causative organism. 2

From the Research

Alternatives to Ertapenem

There are no oral antibiotics that are direct substitutes for ertapenem, as ertapenem is a parenteral carbapenem antimicrobial. However, some oral antibiotics may be used as alternatives in certain situations:

  • Ceftriaxone and piperacillin/tazobactam have been shown to have equivalent efficacy and safety compared to ertapenem in the treatment of community-acquired infections such as complicated intra-abdominal infection, acute pelvic infection, complicated skin and soft-structure infection, community-acquired pneumonia, and complicated urinary tract infections 3.
  • Other oral antibiotics such as fluoroquinolones or beta-lactam/beta-lactamase inhibitors may be used as alternatives, but their efficacy and safety compared to ertapenem are not well established.

Limitations of Oral Antibiotics

Oral antibiotics may not be suitable for all patients, particularly those with severe or complicated infections, as they may not provide adequate coverage or penetration into the site of infection. Ertapenem, on the other hand, has a broad spectrum of activity and can be used to treat a variety of infections, including those caused by multidrug-resistant organisms 4.

Ertapenem's Unique Characteristics

Ertapenem has unique characteristics that make it useful in specific clinical circumstances, such as its once-daily dosing and stability when mixed, which make it suitable for outpatient parenteral antimicrobial therapy (OPAT) 5, 4. However, its limited activity against certain organisms, such as Pseudomonas and Enterococcus, may limit its use in certain situations 4, 3.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Ertapenem: review of a new carbapenem.

Expert review of anti-infective therapy, 2005

Research

Ertapenem.

Expert opinion on pharmacotherapy, 2010

Research

Ertapenem: a new opportunity for outpatient parenteral antimicrobial therapy.

The Journal of antimicrobial chemotherapy, 2004

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.