What is the recommended use and dosage of Ertapenem (a carbapenem antibiotic) for treating various infections?

Ertapenem: Recommended Use and Dosing

Ertapenem is a once-daily carbapenem antibiotic indicated for mild-to-moderate community-acquired intra-abdominal infections, complicated urinary tract infections, skin/soft tissue infections, community-acquired pneumonia, and acute pelvic infections, with standard adult dosing of 1 g IV once daily. 1, 2

Approved Indications and Clinical Use

Community-Acquired Intra-Abdominal Infections

• For mild-to-moderate community-acquired intra-abdominal infections, ertapenem is recommended as single-agent therapy in adults, providing coverage against common Enterobacteriaceae and anaerobes including Bacteroides fragilis 1
• Ertapenem demonstrates 85.1% clinical cure rates for intra-abdominal infections caused by Enterobacteriaceae 3
• For patients with inadequate or delayed source control, or those at high risk for community-acquired ESBL-producing Enterobacteriaceae, ertapenem 1 g once daily is specifically recommended 1, 4

Duration of Therapy by Clinical Scenario

• For immunocompetent, non-critically ill patients with adequate source control: 4 days of therapy 1, 4
• For immunocompromised or critically ill patients with adequate source control: up to 7 days based on clinical response and inflammatory markers 1, 4
• Patients with ongoing infection beyond 7 days warrant further diagnostic investigation 1, 5

Other Complicated Infections

• Complicated urinary tract infections: 90.5% microbiological cure rate, comparable to ceftriaxone 3
• Complicated skin/soft tissue infections: 81% clinical cure rate 3
• Community-acquired pneumonia: 95% clinical cure rate 3
• Acute pelvic infections: 86.8% clinical cure rate 3

Standard Dosing Regimens

Adults and Adolescents ≥13 Years

• 1 g IV once daily for 5-14 days depending on infection type and clinical response 4, 2
• May be administered as IV infusion over 30 minutes 2

Pediatric Patients (3 Months to 12 Years)

• 15 mg/kg IV every 12 hours (maximum 1 g/day) 1, 2
• For complicated intra-abdominal infections in children: 83.7% clinical cure rate 2

Pediatric Patients (13-17 Years)

• 1 g IV once daily (adult dosing) 1, 2

Microbiological Spectrum

Excellent Activity (MIC₉₀ ≤1 mg/L)

• All Enterobacteriaceae including ESBL-producers: 100% susceptibility in clinical trials 6, 7
• Methicillin-susceptible Staphylococcus aureus: More potent than ceftriaxone and piperacillin-tazobactam 6, 7
• Anaerobes including Bacteroides fragilis group: MIC₉₀ 1-4 mg/L 7
• Streptococcus species including S. pneumoniae, S. pyogenes, S. agalactiae: 100% susceptibility 6
• Haemophilus influenzae* and *Moraxella catarrhalis: 100% susceptibility 6

Limited or No Activity

• Pseudomonas aeruginosa: Not adequately covered 8, 7
• Acinetobacter species: Not adequately covered 8, 7
• Enterococcus species: Not adequately covered 1, 7
• Methicillin-resistant Staphylococcus aureus (MRSA): Resistant 7

Critical Clinical Considerations

When NOT to Use Ertapenem

• For septic shock or critically ill patients requiring anti-pseudomonal coverage, switch to meropenem 1 g q6h by extended infusion, doripenem 500 mg q8h by extended infusion, or imipenem/cilastatin 500 mg q6h by extended infusion 1, 4, 5
• Not recommended for late-onset nosocomial infections due to limited activity against Pseudomonas, Acinetobacter, and enterococci 8
• Not recommended for high-severity community-acquired infections requiring broader coverage 1

Antimicrobial Stewardship Concerns

• The Infectious Diseases Society of America expresses concern that broad use of ertapenem may hasten emergence of carbapenem-resistant Enterobacteriaceae, Pseudomonas, and Acinetobacter species 1
• Reserve for appropriate indications rather than routine empiric use 1

Special Populations Requiring Dose Adjustment

• Critically ill patients and those with BMI >20 kg/m²: Standard 1 g once-daily dosing may not provide adequate free drug concentrations; consider shortening dosing interval or continuous infusion 8
• Renal impairment: Dose adjustment necessary 5

Biliary and Cholangitis Infections

Complicated Cholecystitis

• For critically ill or immunocompromised patients with complicated cholecystitis and adequate source control: ertapenem 1 g once daily for 4 days 1
• For patients with inadequate/delayed source control or high risk for ESBL-producing organisms: ertapenem 1 g once daily 1

Cholangitis

• For patients with cholangitis at high risk for ESBL-producing Enterobacteriaceae: ertapenem 1 g once daily for 4 days with adequate source control 1
• Biliary drainage plus antibiotic therapy required 1

Surgical Prophylaxis

• For elective colorectal surgery: single dose of ertapenem demonstrated 70.5% prophylactic success rate versus 57.2% for cefotetan (p<0.001), though clinical superiority not definitively established 2
• Administer no more than 2 hours prior to surgical incision 2

Pharmacodynamic Optimization

• Time above MIC (T>MIC) of 100% correlates with optimal clinical response in severe infections 5
• Free drug concentrations remain above MIC₉₀ for susceptible organisms for at least 8-24 hours post-infusion 6

Common Pitfalls to Avoid

• Do not use for empiric coverage of enterococci in community-acquired intra-abdominal infections—enterococcal coverage is unnecessary 1
• Do not use for empiric antifungal coverage of Candida in community-acquired infections 1
• Avoid in patients recently treated with quinolones if considering moxifloxacin instead, as quinolone-resistant organisms are likely 1
• Do not continue beyond 7 days without reassessment—persistent infection requires diagnostic workup 1, 4, 5