ertapenem sodium
Invanz

Available forms
Available by prescription only
Injection: 1 g

Indications and dosages
 Complicated intra-abdominal infections caused by Escherichia coli, Clostridium clostridiiforme, Eubacterium lentum, Peptostreptococcus species, Bacteroides fragilis, B. distasonis, B. ovatus, B. thetaiotaomicron, B. uniformis. Adults: 1 g I.V. or I.M. once daily for 5 to 14 days.
 Complicated skin and skin-structure infections caused by Staphylococcus aureus (methicillin-susceptible strains), Streptococcus pyogenes, E. coli, Peptostreptococcus species. Adults: 1 g I.V. or I.M. once daily for 7 to 14 days.
 Community-acquired pneumonia caused by S. pneumoniae (penicillin-susceptible strains), Haemophilus influenzae (beta-lactamase-negative strains), Moraxella catarrhalis. Adults: 1 g I.V. or I.M. once daily for 10 to 14 days. If clinical improvement occurs after at least 3 days of treatment, appropriate oral therapy may be used to complete the full course of therapy.
 Complicated urinary tract infections, including pyelonephritis caused by E. coli, Klebsiella pneumoniae. Adults: 1 g I.V. or I.M. once daily for 10 to 14 days. After at least 3 days of treatment, if clinical improvement occurs, appropriate oral therapy may be used to complete the full course of therapy.
 Acute pelvic infections including postpartum endomyometritis, septic abortion, and postsurgical gynecologic infections caused by S. agalactiae, E. coli, B. fragilis, Porphyromonas asaccharolyticus, Peptostreptococcus species, Prevotella bivia. Adults: 1 g I.V. or I.M. once daily for 3 to 10 days.
≡ Dosage adjustment. Patients with creatinine clearance of 30 ml/ minute or less or end-stage renal insufficiency (creatinine clearance of 10 ml/minute or less) should receive 500 mg daily. If dose is given less than 6 hours before hemodialysis, give a supplementary dose of 150 mg postdialysis.

Pharmacodynamics
Anti-infective action: The bactericidal activity of ertapenem results from the inhibition of cell wall synthesis and is mediated through ertapenem binding to penicillin-binding proteins. Ertapenem has in vitro activity against gram-positive bacteria: Staphylococcus aureus (methicillin-susceptible strains only), Streptococcus agalactiae, S. pneumoniae (penicillin-susceptible strains only), S. pyogenes; gram-negative bacteria: Escherichia coli, Haemophilus influenzae (beta-lactamase-negative strains only), Klebsiella pneumoniae, Moraxella catarrhalis; and anaerobic bacteria: Bacteroides fragilis, B. distasonis, B. ovatus, B. thetaiotaomicron, B. uniformis, Clostridium clostridiiforme, Eubacterium lentum, Peptostreptococcus species, Porphyromonas asaccharolyticus, and Prevotella bivia.
Methicillin-resistant staphylococci and Enterococcus species are resistant to ertapenem.
Ertapenem is stable against hydrolysis by a variety of beta-lactamases, including penicillinases, cephalosporinases, and extended-spectrum beta-lactamases. Ertapenem is hydrolyzed by metallo-beta-lactamases.

Pharmacokinetics
Absorption: Almost completely absorbed after I.M. administration. Mean bioavailability of 90%.
Distribution: Highly bound to plasma proteins, primarily albumin.
Metabolism: Doesn’t inhibit metabolism mediated by any of the following cytochrome P-450 isoforms: 1A2, 2C9, 2C19, 2D6, 2E1, and 3A4.
Excretion: Eliminated primarily by the kidneys. Mean plasma half-life in adults is about 4 hours.

Contraindications and precautions
Contraindicated in patients hypersensitive to drug, its components, or other drugs in the same class and in those who have had anaphylactic reactions to beta-lactams. I.M. use is contraindicated in patients hypersensitive to local anesthetics of the amide type (because lidocaine hydrochloride is used as a diluent).
 Use cautiously in patients with CNS disorders, compromised renal function, or both because seizures may occur in these patients. Also use cautiously when administering I.M. to avoid inadvertent injection into a blood vessel.

Interactions
Drug-drug. Probenecid: Reduces renal clearance and increases half-life. Don’t give with probenecid to extend half-life.

Adverse reactions
CNS: asthenia, fatigue, anxiety, altered mental status, dizziness, headache, insomnia, fever.
CV: phlebitis, thrombophlebitis, edema, swelling, chest pain, hypertension, hypotension, tachycardia.
EENT: pharyngitis.
GI: abdominal pain, acid regurgitation, oral candidiasis, constipation, diarrhea, dyspepsia, nausea, vomiting.
GU: vaginitis.
Musculoskeletal: leg pain.
Respiratory: cough, dyspnea, rales, rhonchi, respiratory distress.
Skin: erythema, pruritus, rash, extravasation, infused vein complication.

Effects on lab test results
• May increase albumin, ALT, AST, alkaline phosphatase, creatinine, glucose, potassium, and bilirubin levels.
• May increase PT, eosinophil count, and urinary RBC or WBC counts. May decrease hemoglobin, hematocrit, and segmented neutrophil and WBC counts. May increase or decrease platelet count.

Overdose and treatment
Signs and symptoms of overdose may include nausea, diarrhea, and dizziness.
 Stop ertapenem and treat supportively until renal elimination takes place. Ertapenem can be removed by hemodialysis.

Special considerations
• Check for previous penicillin, cephalosporin, or other beta-lactam hypersensitivity before first dose.
• Check for hypersensitivity to local anesthetics of the amide type if dose is to be given I.M.
• Obtain specimens for culture and sensitivity testing before giving first dose. Therapy may start before test results are available.
• Don’t use diluents containing dextrose (alpha-D-glucose). Don’t mix or infuse with other drugs.
• For I.V. administration, reconstitute contents of 1-g vial with 10 ml of water for injection, normal saline injection, or bacteriostatic water for injection. Shake well to dissolve and immediately transfer contents of reconstituted vial to 50 ml of normal saline injection. Infuse over 30 minutes. Complete infusion within 6 hours of reconstitution.
• For I.M. administration, reconstitute contents of 1-g vial with 3.2 ml of 1% lidocaine hydrochloride injection (without epinephrine). Refer to prescribing information for lidocaine hydrochloride. Shake vial thoroughly to form solution. Immediately withdraw contents of vial and give by deep I.M. injection into large muscle, such as the gluteal muscles or lateral part of the thigh. Use reconstituted I.M. solution within 1 hour after preparation. Don’t give reconstituted solution I.V.
• Don’t store lyophilized powder above 77° F (25° C). The reconstituted solution, immediately diluted in normal saline injection, may be stored at room temperature (77° F) and used within 6 hours or stored for 24 hours under refrigeration (41° F [5° C]) and used within 4 hours after removal from refrigeration. Don’t freeze solutions of ertapenem.
 ALERT If allergic reaction occurs, stop drug immediately. Serious anaphylactic reactions require immediate emergency treatment with epinephrine, oxygen, I.V. steroids, and airway management.
• Continue anticonvulsants in patient with known seizure disorders. If focal tremors, myoclonus, or seizures occur, evaluate patient neurologically and give anticonvulsants if not done earlier. Reexamine dosage of ertapenem to determine whether it should be decreased or discontinued.
• If diarrhea persists during therapy, stop drug and collect stool specimen for culture to rule out pseudomembranous colitis.
• Monitor renal, hepatic, and hematopoietic function during prolonged therapy.
• Methicillin-resistant staphylococci and Enterococcus species are resistant to ertapenem.
Pregnant patients
• Use in pregnant women only if clearly needed.
Breast-feeding patients
• Ertapenem appears in breast milk. Give drug to breast-feeding women only when expected benefit outweighs the risk.
Pediatric patients
• Safety and effectiveness haven’t been established.
Geriatric patients
• Select dosage carefully. Monitor renal function.

Patient education
• Inform patient of potential adverse reactions.
• Tell patient to report discomfort at injection site.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use