Usage
Ertapenem is a broad-spectrum antibiotic prescribed for various bacterial infections. It is classified as a carbapenem, belonging to the beta-lactam class of antibiotics. Ertapenem exerts its bactericidal effect by inhibiting bacterial cell wall synthesis. It binds to penicillin-binding proteins (PBPs), ultimately leading to cell death. It demonstrates efficacy against a wide range of gram-positive and gram-negative bacteria, including Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus, but not Pseudomonas aeruginosa or Enterococcus species. It’s commonly used to treat community-acquired pneumonia, complicated intra-abdominal infections, complicated skin and skin structure infections, complicated urinary tract infections (including pyelonephritis), acute pelvic infections, and as prophylaxis for surgical site infections following elective colorectal surgery.
Alternate Names
Invanz (brand name)
How It Works
Pharmacodynamics: Ertapenem exhibits time-dependent bactericidal activity, meaning its efficacy is correlated with the duration for which its concentration remains above the minimum inhibitory concentration (MIC) of the target bacteria.
Pharmacokinetics:
- Absorption: Following intramuscular administration, ertapenem is rapidly and completely absorbed, reaching peak plasma concentrations within 2 hours. Intravenous administration results in peak plasma concentrations at the end of the infusion.
- Distribution: Ertapenem is widely distributed throughout the body, including various tissues and fluids. It exhibits moderate protein binding (approximately 95%).
- Metabolism: Ertapenem is primarily hydrolyzed to an inactive metabolite. This hydrolysis is primarily chemical rather than enzymatic and occurs in plasma.
- Elimination: The inactive metabolite is predominantly eliminated via renal excretion (approximately 80%), with a small portion excreted in the feces (approximately 10%). The elimination half-life is approximately 4 hours.
Mode of Action: Ertapenem inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), which are essential for the cross-linking of peptidoglycans, the main component of the bacterial cell wall. This binding disrupts the cell wall integrity, leading to bacterial cell lysis and death.
Dosage
Standard Dosage
Adults: 1 g once daily intravenously or intramuscularly.
Children (3 months to 12 years): 15 mg/kg twice daily (not to exceed 1 g/day) intravenously or intramuscularly. Safety and efficacy in children below 3 months of age haven’t been established.
Special Cases:
- Elderly Patients: No dosage adjustment is typically necessary unless significant renal impairment is present.
- Patients with Renal Impairment:
- Creatinine Clearance (CrCl) > 30 mL/min: No adjustment needed.
- CrCl ≤ 30 mL/min: 500 mg once daily.
- Hemodialysis: If administered within 6 hours of hemodialysis, give a supplemental dose of 150 mg after dialysis.
- Patients with Hepatic Dysfunction: No dosage adjustment is needed.
- Patients with Comorbid Conditions: No specific dosage adjustments indicated, though clinical judgment should be exercised.
Clinical Use Cases
- Intubation/Surgical Procedures/Mechanical Ventilation/ICU Use: Standard dosage as mentioned above.
- Emergency Situations: Standard dosage can be employed.
Dosage Adjustments
Dose modification is primarily based on renal function.
Side Effects
Common Side Effects:
Diarrhea, nausea, vomiting, headache, infusion site reactions (pain, redness, swelling).
Rare but Serious Side Effects:
Clostridium difficile-associated diarrhea, seizures (rare), allergic reactions (including anaphylaxis), Stevens-Johnson syndrome, toxic epidermal necrolysis.
Long-Term Effects: Generally, no long-term effects are associated with short-term use. Prolonged use may increase the risk of developing C. difficile infection.
Adverse Drug Reactions (ADR): Severe allergic reactions, C. difficile infection, seizures.
Contraindications
Hypersensitivity to ertapenem or other carbapenems.
Drug Interactions
Probenecid can increase ertapenem serum concentrations. Valproic acid levels may be reduced when co-administered with ertapenem.
Pregnancy and Breastfeeding
- Pregnancy: Ertapenem crosses the placenta. Use only if clearly needed. Animal studies have shown adverse effects.
- Breastfeeding: Ertapenem is present in human milk. Exercise caution. Consider the developmental and health benefits of breastfeeding along with the mother’s clinical need for ertapenem and any potential adverse effects on the breastfed child from ertapenem or from the underlying maternal condition.
Drug Profile Summary
- Mechanism of Action: Inhibits bacterial cell wall synthesis by binding to PBPs.
- Side Effects: Diarrhea, nausea, vomiting, headache. Rarely: seizures, C. difficile infection, allergic reactions.
- Contraindications: Hypersensitivity to ertapenem or other carbapenems.
- Drug Interactions: Probenecid, valproic acid.
- Pregnancy & Breastfeeding: Use with caution. Discuss risks and benefits with the patient.
- Dosage: Adults: 1 g once daily IV/IM. Children (3 months-12 years): 15 mg/kg twice daily IV/IM (max 1 g/day). Adjust for renal impairment.
- Monitoring Parameters: Renal function, signs of superinfection (e.g., C. difficile infection).
Popular Combinations
No specific popular combinations to highlight.
Precautions
Assess renal function prior to and during therapy. Monitor for signs of superinfection, particularly C. difficile infection.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Ertapenem?
A: Adults: 1 g once daily IV/IM. Children (3 months-12 years): 15 mg/kg twice daily IV/IM (max 1 g/day). Adjust dosage for renal impairment.
Q2: How is Ertapenem administered?
A: Intravenously (over 30 minutes) or intramuscularly.
Q3: What are the common side effects of Ertapenem?
A: Diarrhea, nausea, vomiting, headache, and injection site reactions.
Q4: What are the contraindications to using Ertapenem?
A: Hypersensitivity to ertapenem or other carbapenems.
Q5: How does Ertapenem interact with other drugs?
A: Can interact with probenecid (increased ertapenem levels) and valproic acid (decreased valproic acid levels).
Q6: Can Ertapenem be used in pregnancy or breastfeeding?
A: Use with caution in both pregnancy and breastfeeding. Weigh the benefits against the risks. Consult available guidelines.
Q7: What is the mechanism of action of Ertapenem?
A: Inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs).
Q8: What are the serious side effects of Ertapenem?
A: Seizures, Clostridium difficile-associated diarrhea, serious allergic reactions (including anaphylaxis).
Q9: How should Ertapenem dosage be adjusted for patients with renal impairment?
A: For CrCl ≤ 30 mL/min: 500 mg once daily. For hemodialysis patients, if given within 6 hours of dialysis, give a supplemental 150 mg dose post-dialysis.
Q10: What infections is Ertapenem commonly used to treat?
A: Community-acquired pneumonia, complicated intra-abdominal infections, complicated skin and skin structure infections, complicated urinary tract infections (including pyelonephritis), acute pelvic infections, and surgical prophylaxis for elective colorectal surgery.
