Ertapenem (Invanz) Dosage for Septicemia
For septicemia treatment, ertapenem should be administered at a dose of 1 g once daily for 4-7 days, with duration based on clinical response and patient factors. 1
Dosing Recommendations
- Ertapenem 1 g IV once daily is the standard dose for septicemia, particularly in patients with inadequate source control or at high risk of infection with ESBL-producing Enterobacterales 1
- For critically ill patients with septic shock, consider alternative carbapenems such as meropenem 1 g q6h by extended infusion, doripenem 500 mg q8h by extended infusion, or imipenem/cilastatin 500 mg q6h by extended infusion 1
- Administration can be via intravenous or intramuscular routes, with 92% bioavailability for intramuscular administration 2
Duration of Therapy
- For immunocompetent and non-critically ill patients with adequate source control: 4 days of antibiotic therapy 1
- For immunocompromised or critically ill patients with adequate source control: up to 7 days based on clinical conditions and inflammatory markers 1
- Patients with ongoing signs of infection beyond 7 days warrant further diagnostic investigation 1
- For severe infections with sepsis, the Infectious Diseases Society of America suggests treatment courses of 10-14 days 3
Pharmacokinetic Considerations
- Ertapenem has a half-life of approximately 4 hours, allowing for once-daily dosing 4, 5
- Protein binding is high (92-95%), with nonlinear binding characteristics 5
- Approximately 45% of plasma clearance is via renal clearance, with the remainder primarily through formation of beta-lactam ring-opened metabolites 5
- No accumulation occurs after multiple once-daily dosing 2, 5
Special Populations
- No clinically significant differences in pharmacokinetics between men and women 5
- For patients with renal impairment, dose adjustment may be necessary (though specific adjustments not detailed in the provided evidence)
- For critically ill septic patients, continuous infusion of ertapenem provides equally effective pharmacokinetic/pharmacodynamic parameters as intermittent infusion in patients with normal weight and good renal function 6
Clinical Efficacy
- Ertapenem demonstrates excellent activity against cephalosporin-resistant enteric organisms producing extended-spectrum beta-lactamases (ESBLs) or AmpC beta-lactamases 4
- In urinary tract infections, high ertapenem concentrations (>128 mg/L) can be maintained in urine for 40% of the dosing interval 7
Monitoring
- Patients should be monitored for clinical response, with particular attention to resolution of sepsis markers 1
- If signs of infection persist beyond the recommended treatment duration, further diagnostic evaluation is warranted 1
Important Caveats
- Ertapenem has restricted activity against nosocomial pathogens such as Pseudomonas aeruginosa, Acinetobacter species, methicillin-resistant staphylococci, and enterococci 4
- For septic shock, consider alternative carbapenems with broader coverage against resistant pathogens 1
- For beta-lactams like ertapenem, the key pharmacodynamic correlate to clinical response is time above MIC (T>MIC), with optimal response in severe infections achieved with T>MIC of 100% 1