Ertapenem

The bactericidal activity of ertapenem results from the inhibition of cell wall synthesis and is mediated through ertapenem binding to penicillin binding proteins (PBPs). In Escherichia coli, it has strong affinity toward PBPs 1a, 1b, 2, 3, 4 and 5 with preference for PBPs 2 and 3. Ertapenem is stable against hydrolysis by a variety of beta-lactamases, including penicillinases, and cephalosporinases and extended spectrum beta-lactamases. Ertapenem is hydrolyzed by metallo-beta-lactamases.

Ertapenem should be infused over 30 minutes in both the Treatment and Prophylactic regimens. Dosing considerations should be made in adults with advanced or end-stage renal impairment and those on hemodialysis.

Treatment regimen:

• Adults and pediatric patients 13 years of age and older. The dosage should be 1 gram once a day intravenously or intramuscularly.
• Patients 3 months to 12 years of age should be administered 15 mg/kg twice daily (not to exceed 1 g/day intravenously or intramuscularly.)
• Intravenous infusion may be administered in adults and pediatrics for up to 14 days or intramuscular injection for up to 7 days.

Prophylaxis regimen for adults:

• 1 gram single dose given 1 hour prior to elective colorectal surgery.

• Co-administration with probenecid inhibits the renal excretion of ertapenem and is therefore not recommended.
• The concomitant use of ertapenem and valproic acid/divalproex sodium is generally not recommended. Anti-bacterials other than carbapenems should be considered to treat infections in patients whose seizures are well controlled on valproic acid or divalproex sodium.

Known hypersensitivity to product components or anaphylactic reactions to β-lactams. Due to the use of lidocaine HCl as a diluent, Ertapenem administered intramuscularly is contraindicated in patients with a known hypersensitivity to local anesthetics of the amide-type.

Adults: The most common adverse reactions (≥5%) in patients treated with Ertapenem, including those who were switched to therapy with an oral antimicrobial, were diarrhea, nausea, headache and infused vein complication. In the prophylaxis indication, the overall adverse experience profile was generally comparable to that observed for ertapenem in other clinical trials.

Pediatrics: Adverse reactions in this population were comparable to adults. The most common adverse reactions (≥5%) in pediatric patients treated with Ertapenem, including those who were switched to therapy with an oral antimicrobial, were diarrhea, vomiting and infusion site pain.

Pregnancy Category B. There are, however, no adequate and well-controlled trials in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed. Ertapenem is excreted in human breast milk. Caution should be exercised when Ertapenem is administered to a nursing woman. Ertapenem should be administered to nursing mothers only when the expected benefit outweighs the risk.

• Serious hypersensitivity (anaphylactic) reactions have been reported in patients receiving β-lactams.
• Seizures and other central nervous system adverse experiences have been reported during treatment.
• Co-administration of Ertapenem with valproic acid or divalproex sodium reduces the serum concentration of valproic acid potentially increasing the risk of breakthrough seizures.
• Clostridium deficits-associated diarrhea (ranging from mild diarrhea to fatal colitis): Evaluate if diarrhea occurs.
• Caution should be taken when administering Ertapenem intramuscularly to avoid inadvertent injection into a blood vessel.

Pediatric Use: Safety and effectiveness of Ertapenem in pediatric patients 3 months to 17 years of age are supported by evidence from adequate and well-controlled trials in adults, pharmacokinetic data in pediatric patients, and additional data from comparator-controlled trials in pediatric patients 3 months to 17 years of age.

Geriatric Use: This drug is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function

Patients with Renal Impairment: Dosage adjustment is necessary in patients with creatinine clearance 30 mL/min or less.

Patients with Hepatic Impairment: The pharmacokinetics of ertapenem in patients with hepatic impairment have not been established.

Other beta-lactam Antibiotics

No specific information is available on the treatment of overdosage with Ertapenem. Intentional overdosing of Ertapenem is unlikely. Intravenous administration of Ertapenem at a dose of 2 g over 30 min or 3 g over 1-2h in healthy adult volunteers resulted in an increased incidence of nausea. In clinical trials in adults, inadvertent administration of three 1 g doses of Ertapenem in a 24 hour period resulted in diarrhea and transient dizziness in one patient. In pediatric clinical trials, a single intravenous dose of 40 mg/kg up to a maximum of 2 g did not result in toxicity. In the event of an overdose, Ertapenem should be discontinued and general supportive treatment given until renal elimination takes place. Ertapenem can be removed by hemodialysis; the plasma clearance of the total fraction of ertapenem was increased 30% in subjects with end-stage renal disease when hemodialysis (4 hour session) was performed immediately following administration. However, no information is available on the use of hemodialysis to treat overdosage.

Ertapenem 1 g single dose should be prepared with diluent containers containing 50 mL or 100 mL of 0.9% Sodium Chloride Injection. When prepared with this diluent, Ertapenem for Injection maintains satisfactory potency for 6 hours at room temperature (25°C) or for 24 hours under refrigeration (5°C) and used within 4 hours after removal from refrigeration. Solutions of Ertapenem should not be frozen.