#ertapenem

Common Brand Names: Invanz

Therapeutic Class: A carbapenem antibiotic

Common Injectable Dosage Forms:

Powder for Injection: 1-gram vials

Dosage Ranges:

Treatment of complicated intra-abdominal infections due to E. coli, C. clostridioforme, E. lentum, Peptostreptococcus species, B. fragilis, B. distasonis, B. ovatus, B. thetaiotaomicron, or B. uniformis: 1 gram given once a day for 5-14 days.

Treatment of complicated skin and skin structure infections due to S. aureus (methicillin susceptible strains), S. Pyogenes, E. coli, or Peptostreptococcus species: 1 gram given once a day for 7-14 days.

Treatment of community-acquired pneumonia due to S. pneumoniae (penicillin susceptible strains) including cases with concurrent bacteremia, H. influenzae (beta-lactamase negative strains), or M. catarrhalis: 1 gram given once a day for 10-14 days.

Treatment of complicated urinary tract infections including pyelonephritis due to E. coli, including cases with concurrent bacteremia, or K. pneumonia: 1 gram given once a day for 10-14 days.

Treatment of acute pelvic infections including postpartum endomyometritis, septic abortion, and post-surgical gynecologic infections due to S. agalactiae, E. coli, B. fragilis, P. asaccharolytica, Peptostreptococcus species, or P. bivia: 1 gram given once a day for 3-10 days.

Dosage in patients with creatinine clearance ≤30 mL/min/1.73 m3 and end-stage renal insufficiency: 500 mg given once a day (at least 6 hours prior to hemodialysis).

Administration and Stability: Ertapenem may be given by IV infusion for up to 14 days or by IM injection for up to 7 days. IV infusions should be given over a period of 30 minutes. Preparations for IV infusion: Reconstitute a vial with 10 mL of a compatible solution (Water for Injection, 0.9% Sodium Chloride Injection, or Bacteriostatic Water for Injection). Shake well to dissolve than transfer to 50 mL or 0.9% Sodium Chloride Injection. Diluted solution must be used within 6 hours of reconstitution. Preparation for IM injection: Reconstitute a vial with 3.2 mL of 1.0% lidocaine HCl injection (without epinephrine). Shake well and use within 1 hour of preparation. pH 7.5

Pharmacology/Pharmacokinetics: Ertapenem is a carbapenem antibiotic with bactericidal activity against many gram-positive and gram-negative bacteria. Its mode of action is through inhibition of cell wall synthesis and is mediated through ertapenem binding to penicillin binding proteins. 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. Peak plasma levels after an IM injection occur after 2.3 hours. Ertapenem is eliminated primarily by the kidneys. The mean plasma half-life in healthy adults is approximately 4 hours.

Drug and Lab Interactions: Coadministration with probenecid decreases the renal clearance of ertapenem.

Contraindications/Precautions: Contraindicated in patients hypersensitive to other beta-lactam antibiotics. IM administration is contraindicated in patients allergic to lidocaine. Pseudomembranous colitis has been reported with nearly all antibacterial agents, including ertapenem, and may range in severity from mild to life-threatening. This diagnosis should be considered in patients who present with diarrhea during or after therapy. Use has been associated with a risk of seizures therefore use with caution in patients with brain lesions or a history of seizures. Ertapenem is excreted in breast milk. Pregnancy Category B.

Monitoring Parameters: Periodic renal, hepatic, and hemopoietic assessment; neurologic assessment

Adverse Effects: The most common adverse reactions seen in clinical studies include diarrhea (5.5%), infused vein complication (3.7%), nausea (3.1%), headache (2.2%), vaginitis (2.1%), phlebitis/thrombophlebitis (1.3%), and vomiting (1.1%).