Ertapenem
Overview
Ertapenem is a parenteral carbapenem antibiotic in the beta-lactam class with broad-spectrum bactericidal activity against many aerobic and anaerobic Gram-positive and Gram-negative bacteria. It exerts its effect by binding to bacterial penicillin-binding proteins and inhibiting cell wall synthesis, leading to bacterial cell death. Unlike some other carbapenems, ertapenem is stable against many beta-lactamases and does not require a dehydropeptidase inhibitor. It is administered by intravenous infusion or intramuscular injection, typically once daily due to its relatively long half-life. Ertapenem’s spectrum excludes many strains of Pseudomonas and Acinetobacter, and it is commonly used in hospitalized adults for community-acquired and complicated infections where susceptible pathogens are expected or confirmed. Its predictable pharmacokinetics and once-daily dosing facilitate use in a range of moderate to severe bacterial infections, particularly when resistance to other agents is a concern.
Background and Date of Approval
Ertapenem was approved for medical use in the United States by the Food and Drug Administration on November 21, 2001 under the trade name Invanz for the treatment of moderate to severe infections caused by susceptible organisms. It received approval in the European Union in April 2002 for similar indications. Over time, regulatory updates expanded pediatric indications and labeling revisions based on post-marketing safety and clinical trial data. Ertapenem has since been widely incorporated into clinical practice guidelines for management of complicated bacterial infections.
Uses
Ertapenem is indicated for the treatment of complicated intra-abdominal infections, complicated skin and soft tissue infections, community-acquired pneumonia, acute pelvic infections including gynecologic and post-surgical pelvic infections, diabetic foot infections of the skin and soft tissue, and complicated urinary tract infections including pyelonephritis when caused by susceptible bacteria. It is also approved for prophylaxis of surgical site infection following elective colorectal surgery in adults. It is used as monotherapy in infections caused by susceptible organisms, particularly where mixed aerobic and anaerobic coverage is required.
Administration
Ertapenem is administered by intravenous infusion over approximately 30 minutes or by intramuscular injection once daily in adults. The standard adult dose for most approved indications is 1 gram administered every 24 hours. Dosage adjustments are required in patients with moderate to severe renal impairment due to renal elimination of the drug. In pediatric patients aged three months and older, dosing is weight-based according to approved labeling. Treatment duration depends on infection severity, site of infection, and clinical response, generally ranging from five to 14 days or longer for complicated infections. Monitoring includes clinical response and periodic assessment of renal function.
Side Effects
Frequently reported adverse effects with ertapenem include diarrhea, nausea, vomiting, headache, rash, pruritus, and injection or infusion site reactions. Mild elevations in liver enzymes may occur during therapy. Most adverse events are mild to moderate in intensity and resolve after completion or discontinuation of treatment.
Warnings
Serious adverse reactions may include hypersensitivity reactions such as anaphylaxis in patients with a history of beta-lactam allergy. Seizures and encephalopathy have been reported, particularly in patients with significant renal impairment or central nervous system disorders. Clostridioides difficile-associated diarrhea is a potential complication associated with broad-spectrum antibiotic use. Ertapenem should not be used in patients with known severe hypersensitivity to carbapenems or other beta-lactam antibiotics.
Precautions
Baseline renal function assessment is recommended prior to initiation and during therapy to guide dosing adjustments. Caution is required in patients with a history of hypersensitivity to penicillins or cephalosporins due to possible cross-reactivity. Ertapenem may significantly reduce plasma concentrations of valproic acid, potentially decreasing seizure control, and alternative anticonvulsant management may be necessary. Concomitant use with nephrotoxic medications warrants monitoring of renal function.
Expert Tips
Appropriate patient selection should consider local antimicrobial resistance patterns and microbiological culture results whenever available. Renal dose adjustment is essential to reduce the risk of neurotoxicity. Patients should be counselled regarding potential gastrointestinal symptoms and instructed to report signs of allergic reaction or neurologic changes promptly. Integration of ertapenem into antimicrobial stewardship programs can help optimize outcomes while minimizing resistance development.