Ertapen

Approved Indications:

• Complicated Intra-Abdominal Infections (cIAI) in adults and pediatric patients ≥3 months.
• Complicated Skin and Skin Structure Infections (cSSSI), including diabetic foot infections without osteomyelitis.
• Community-Acquired Pneumonia (CAP) in adults.
• Complicated Urinary Tract Infections (cUTI), including pyelonephritis.
• Acute Pelvic Infections, including postpartum endomyometritis, septic abortion, and post-surgical gynecologic infections.
• Prophylaxis of Surgical Site Infections following elective colorectal surgery.

Important Off-Label (Clinically Accepted) Uses:

• Treatment of ESBL-producing Enterobacteriaceae in bloodstream infections or urinary tract infections.
• Alternative agent in multidrug-resistant Gram-negative infections where susceptibility is confirmed.
• Off-label use in osteomyelitis when caused by susceptible pathogens.

Adults:

• Standard Dose: 1 g IV once daily, infused over 30 minutes.
• Duration: Typically 5–14 days depending on infection type and severity.

Pediatrics (≥3 months to 12 years):

• 15 mg/kg IV every 12 hours (maximum 1 g/day).

Pediatrics (13–17 years):

• 1 g IV once daily.

Elderly:

• No dose adjustment required unless renal impairment is present.

Renal Impairment:

• CrCl ≥30 mL/min: No adjustment.
• CrCl <30 mL/min: 500 mg IV once daily.
• Hemodialysis: Not recommended (insufficient data).

Hepatic Impairment:

• No dose adjustment necessary.

Route of Administration:

• Intravenous infusion (preferred).
• Intramuscular injection (can be used with 1% lidocaine solution).

Ertapenem is a carbapenem-class beta-lactam antibiotic that exerts bactericidal activity by binding to and inactivating penicillin-binding proteins (PBPs) on the bacterial cell wall. This inhibits the final step in peptidoglycan synthesis, weakening the cell wall and leading to cell lysis. Its broad spectrum includes many Gram-negative, Gram-positive, and anaerobic bacteria, but it notably lacks activity against Pseudomonas aeruginosa and Acinetobacter species.

• Absorption: Not orally bioavailable; administered IV or IM.
• Bioavailability: IM injection provides complete systemic availability.
• Distribution: Widely distributed; protein binding ~85-95%.
• Metabolism: Minimally metabolized.
• Half-life: ~4 hours in healthy adults.
• Elimination: Primarily via renal excretion (glomerular filtration and tubular secretion).
• Excretion: ~80% unchanged in urine.

• Pregnancy: Classified as Pregnancy Category B. Animal studies have not demonstrated fetal risk; however, human data are limited. Use only if clearly needed.
• Lactation: Ertapenem is excreted in small amounts in human milk. Due to potential for serious adverse reactions in nursing infants (e.g., diarrhea, candidiasis), caution is advised. Temporary discontinuation of breastfeeding may be considered.

• Primary Class: Carbapenem Antibiotic
• Subclass: Beta-lactam antibacterial; Monocyclic β-lactam ring
• Spectrum: Broad-spectrum, excluding Pseudomonas and Acinetobacter

• Known hypersensitivity to Ertapenem, other carbapenems, or any of its components.
• History of severe hypersensitivity (e.g., anaphylaxis) to beta-lactams (e.g., penicillins, cephalosporins).
• Children under 3 months of age (safety not established).
• Intramuscular route contraindicated in patients allergic to lidocaine.

• Seizure Risk: Especially in patients with CNS disorders or renal dysfunction.
• Superinfection: Prolonged use may result in fungal or bacterial superinfections, including C. difficile–associated diarrhea.
• Hematologic Effects: Monitor for thrombocytopenia, leukopenia, eosinophilia, and anemia during long-term therapy.
• Hepatic Impairment: Although no dose adjustment is needed, liver function should be monitored.
• Renal Impairment: Increases plasma levels; dose adjustment required.
• Cross-Sensitivity: Use with caution in patients allergic to other beta-lactams.
• Hypersensitivity Reactions: Including anaphylaxis and skin rash.

Common (≥1%):

• Gastrointestinal: Diarrhea, nausea, vomiting, abdominal pain
• Injection Site: Phlebitis, pain, inflammation
• Skin: Rash, pruritus
• CNS: Headache, dizziness

Less Common/Rare:

• Hematologic: Neutropenia, eosinophilia, thrombocytopenia
• Hepatic: Elevated liver enzymes
• Renal: Increased serum creatinine
• Severe: Seizures (rare, mostly in those with renal impairment or CNS conditions), anaphylaxis

Onset: Most side effects appear during treatment and are reversible upon discontinuation.

• Probenecid: Inhibits renal excretion, increasing Ertapenem levels—co-administration not recommended.
• Valproic Acid: May reduce serum valproic acid levels, increasing seizure risk.
• Live Vaccines: May diminish efficacy of live bacterial vaccines (e.g., typhoid); avoid concurrent use.
• Enzyme Systems: Not significantly metabolized by CYP450 enzymes; low potential for cytochrome P450 interactions.

• WHO and IDSA have reaffirmed the role of Ertapenem for treatment of ESBL-producing Enterobacteriaceae in non-ICU settings.
• Recent guidelines caution against its use in infections where Pseudomonas or Acinetobacter are likely, due to lack of activity.
• Updated warnings emphasize seizure risk in renal impairment and co-administration with valproic acid.

• Vials (powder for injection):
• Store at 20°C to 25°C (68°F to 77°F)
• Protect from light and moisture
• Do not freeze
• Reconstituted Solution:
• Use within 6 hours if stored at room temperature
• May be refrigerated at 2°C to 8°C (36°F to 46°F) for up to 24 hours
• Handling:
• Use aseptic technique during reconstitution
• Shake well before use
• Discard unused portion