CEFOTETAN (Generic for CEFOTAN)

General Administration Information
For storage information, see the specific product information within the How Supplied section.

Route-Specific Administration

Injectable Administration
-Visually inspect parenteral products for particulate matter and discoloration prior to administration whenever solution and container permit.
Intravenous Administration
Vial Reconstitution:
-1 g vials: Reconstitute the 1 g vial with 10 mL of Sterile Water for Injection to give an approximate concentration of 95 mg/mL with an approximate withdrawable volume of 10.5 mL. Shake vials until powder is dissolved and let stand until solution is clear.
-2 g vials: Reconstitute the 2 g vial with 10 to 20 mL of Sterile Water for Injection to give an approximate concentration of 95 to 182 mg/mL with an approximate withdrawable volume of 11 to 21 mL. Shake vials until powder is dissolved and let stand until solution is clear.
-10 g bulk vials: Reconstitute the 10 g vial with 50 or 100 mL Sterile Water for Injection, 5% Dextrose Injection, or 0.9% Sodium Chloride Injection to give an approximate concentration of 180 or 95 mg/mL, respectively, and an approximate withdrawable volume of 55 or 105 mL. Shake vials until powder is dissolved and let stand until solution is clear. Withdrawal and transfer from the bulk vials should occur immediately, with a maximum time of 4 hours from the initial introduction of the diluent. Reconstituted solutions must be further diluted.
-Storage: Reconstituted 1 or 2 g vials are stable for 24 hours at room temperature (25 degrees C or 77 degrees F), for 96 hours under refrigeration (5 degrees C or 41 degrees F), and for at least 1 week in the frozen state (-20 degrees C or 4 degrees F). Aliquots reconstituted from bulk vials are stable for 24 hours at room temperature, for 96 hours under refrigeration (5 degrees C or 41 degrees F), and for 1 week in the frozen state.
-Frozen samples from vials should be thawed at room temperature before use. Do not refreeze.

Duplex System Reconstitution (Activation):
-Unlatch side tab and unfold Duplex container.
-To inspect powder, peel foil strip from drug chamber. Protect from light after removal of foil strip.
-Refold and latch side tab until ready to activate.
-If foil strip is removed, use within 7 days.
-Do not use directly after storage by refrigeration. Allow product to equilibrate to room temperature before use.
-To activate, unfold the Duplex container and point the set port in a downward direction. Starting at the hanger tab end, fold the Duplex container just below the diluent meniscus, trapping all of the air above the fold. Squeeze the folded diluent chamber until the seal between the diluent and powder opens, releasing the diluent into the powder chamber.
-Agitate the liquid-powder mixture until the powder is completely dissolved.
-Storage: Use within 12 hours of activation if stored at room temperature or within 5 days if stored under refrigeration. Do not freeze.

IV Push
-Single-dose vials may be used for direct injection after reconstitution. Bulk vials and Duplex containers should not be used for direct injection.
-Inject appropriate dose directly into a vein over 3 to 5 minutes.

Intermittent IV Infusion
-Infuse over approximately 30 minutes.
-Using an infusion system, cefotetan may be administered over a longer period through the tubing system by which the patient may be receiving other IV solutions. Butterfly or scalp vein-type needles are preferred for this type of infusion. However, it is recommended to temporarily discontinue the administration of other solutions at the same site.
-Duplex delivery system: Do not use plastic containers in series connections to avoid air embolism. Point the set port downward, and starting at the hanger tab end, fold the Duplex container just below the solution meniscus, trapping all of the air above the fold. Squeeze the container until the seal between the reconstituted drug solution and set port opens, releasing liquid to the set port. Check for leaks by squeezing before attaching to IV set. Peel the foil cover from the set port and attach a sterile administration set.
-Solutions of cefotetan must not be admixed with solutions containing aminoglycosides. If cefotetan and aminoglycosides are to be administered to the same patient, they must be administered separately and not as a mixed injection.

Intramuscular Administration
Reconstitution
-Reconstitute vials with Sterile Water for Injection, 0.9% Sodium Chloride Injection, 0.5% Lidocaine HCl Injection, 1% Lidocaine HCl Injection, or Bacteriostatic Water for Injection.
-1 g vials: Reconstitute with 2 mL of diluent to give an approximate concentration of 400 mg/mL with an approximate withdrawable volume of 2.5 mL.
-2 g vials: Reconstitute with 3 mL of diluent to give an approximate concentration of 500 mg/mL with an approximate withdrawable volume of 4 mL.
-Shake vials until powder is dissolved and let stand until solution is clear.
-Storage: Reconstituted vials are stable for 24 hours at room temperature (25 degrees C or 77 degrees F), for 96 hours under refrigeration (5 degrees C or 41 degrees F), and for at least 1 week in the frozen state (-20 degrees C or 4 degrees F).

Intramuscular Injection
-Inject deeply into a large muscle mass (e.g., anterolateral thigh or deltoid [children and adolescents only]).

Elevated hepatic enzymes occurred in 1.2% of adult patients receiving cefotetan during clinical trials and included a rise in ALT (SGPT) (0.7%), AST (SGOT) (0.3%), alkaline phosphatase (0.14%), and LDH (0.14%). Hepatic dysfunction, including cholestasis and elevated bilirubin concentrations (hyperbilirubinemia), has been reported with cephalosporins as a class.

Cefotetan can cause hypoprothrombinemia, although the incidence reported in adults has been similar (i.e., 6% to 8%) to the rate with other antibiotic regimens. The risk of actual bleeding is much less. Some reports suggest that the methylthiotetrazole side chain within the drug's structure may be responsible, while others suggest the sulfhydryl group. Monitor prothrombin times in patients at risk (i.e., patients with impaired renal function, patients with impaired hepatobiliary function, patients with a coagulopathy, patients with poor nutritional state, and patients receiving total parenteral nutrition), and give vitamin K as needed, because, in almost all cases, patients who developed hypoprothrombinemia had 1 of these risk factors. Other hematologic abnormalities, such as eosinophilia (0.5% of adults), thrombocytosis (0.3% of adults), and a positive direct Coombs' test (0.4% of adults), have also been reported with cefotetan. Agranulocytosis, leukopenia, thrombocytopenia, and prolonged prothrombin time with or without bleeding have been reported during postmarketing use. Aplastic anemia, neutropenia, pancytopenia, and hemorrhage have occurred with the cephalosporin class of antimicrobials.

A local injection site reaction occurred in adult patients receiving cefotetan and included discomfort (0.2%) and phlebitis (0.3%).

Hypersensitivity reactions were reported in 1.2% of adult patients receiving cefotetan therapy and include rash (0.7%) and pruritus (0.14%). Anaphylactoid reactions and urticaria have been noted in postmarketing reports. Angioedema has also been reported. Side effects that have been reported with the cephalosporins as a class include erythema multiforme, Stevens-Johnson syndrome, and toxic epidermal necrolysis.

Gastrointestinal adverse events occurred in adult patients receiving cefotetan therapy and included diarrhea (1.25%) and nausea (0.14%). Other adverse events that have been reported with the cephalosporins as a class include abdominal pain, colitis, and vomiting.

Microbial overgrowth and superinfection can occur with antibiotic use. C. difficile-associated diarrhea (CDAD) or pseudomembranous colitis has been reported with cefotetan. If pseudomembranous colitis is suspected or confirmed, ongoing antibacterial therapy not directed against C. difficile may need to be discontinued. Institute appropriate fluid and electrolyte management, protein supplementation, C. difficile-directed antibacterial therapy, and surgical evaluation as clinically appropriate. Vaginal candidiasis and vaginitis have been reported with cephalosporin use.

Seizures are rare, but a serious complication of cephalosporin therapy; seizures have been most commonly associated with patients with renal dysfunction receiving dosages that were not properly adjusted. If seizures associated with drug therapy occur, stop cefotetan and administer anticonvulsant therapy as indicated. Seizures have been reported in less than 1% of patients receiving cephalosporins.

Elevations in BUN and serum creatinine (azotemia) and nephrotoxicity have been noted in postmarketing reports with cefotetan. Renal dysfunction and toxic nephropathy have occurred with the cephalosporins as a class. Interstitial nephritis has been reported in less than 1% of patients receiving cephalosporins.

Fever has been reported during postmarketing with cefotetan.

An immune-mediated hemolytic anemia has been observed in patients receiving cephalosporin antibiotics. Severe cases of hemolytic anemia, including fatalities, have been reported with cefotetan during postmarketing. Periodically monitor all patients who receive cefotetan for signs and symptoms of hemolytic anemia, including measurement of hematological parameters when appropriate. If a patient develops anemia anytime within 2 to 3 weeks after cefotetan administration, consider the diagnosis of cephalosporin-associated anemia and stop the drug until the etiology is determined with certainty. Blood transfusions may be considered as needed. There appears to be at least a 3-fold higher risk of developing hemolytic anemia with cefotetan relative to other cephalosporins; cefotetan is among the most common drugs associated with the development of hemolytic anemia.. In a review of adverse event databases, 85 cases of cefotetan-induced hemolytic anemia were identified over an approximately 12-year period. All patients were adults and most had received cefotetan for prophylaxis rather than treatment; 30% had received cefotetan for less than 1 day. Only 18% had received prior cefotetan therapy. A mean hemoglobin decrease of 6.7 g/dL was noted with a final mean hemoglobin of 5.2 g/dL. Fifteen fatalities were reported and renal failure developed in 7 cases.

A false-positive reaction for glucose in the urine may occur in patients receiving cefotetan, and using Benedict's solution, Fehling's solution, or Clinitest tablets for urine glucose testing. However, this reaction has not been observed with glucose oxidase tests (e.g., Tes-tape, Clinistix, Diastix). Patients with diabetes mellitus who test their urine for glucose should use glucose tests based on enzymatic glucose oxidase reactions while on cefotetan treatment.

Positive direct Coombs' tests have been reported during treatment with cefotetan. In hematologic studies or in transfusion cross- matching procedures when antiglobulin tests are performed on the minor side or in Coombs' testing of newborns whose mothers received cefotetan before delivery, clinicians should keep in mind that a positive Coombs' test may be due to the drug.

High concentrations of cefotetan may interfere with serum and urine creatinine measurement using the Jaffe reaction; creatinine concentrations may appear falsely elevated.

Cefotetan is contraindicated in patients with cephalosporin hypersensitivity or cephamycin hypersensitivity. Cefotetan should be used cautiously in patients with hypersensitivity to penicillin. The structural similarity between cefotetan and penicillin causes these patients to be more susceptible to hypersensitivity reactions. Penicillins can cause a variety of hypersensitivity reactions ranging from mild rash to fatal anaphylaxis. Patients who have experienced severe penicillin hypersensitivity should not receive cefotetan. Cross-reactivity to cephalosporins is approximately 3% to 7% with a documented history to penicillin.

Use cefotetan with caution in patients with renal impairment or renal failure because the drug is eliminated via renal mechanisms. Cephalosporins have been associated with seizures, especially in patients with renal impairment given unadjusted doses. Dosage reductions are recommended in these patients.

Consider pseudomembranous colitis in patients presenting with diarrhea after antibacterial use. Careful medical history is necessary as pseudomembranous colitis has been reported to occur over 2 months after the administration of antibacterial agents. Almost all antibacterial agents, including cefotetan, have been associated with pseudomembranous colitis or C. difficile-associated diarrhea (CDAD) which may range in severity from mild to life-threatening. Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile.

Cefotetan is contraindicated in patients who have experienced a cephalosporin-associated hemolytic anemia. There is at least a 3-fold higher risk of developing hemolytic anemia with cefotetan relative to other cephalosporins, and cefotetan is one of the most common drugs associated with the development of hemolytic anemia. In a review of the FDA's spontaneous reporting system (SRS) adverse event database and the World Health Organization's (WHO) database, 85 cases of cefotetan-induced hemolytic anemia were identified over an approximately 12-year period (1985 to 1997). All patients were adults and most had received cefotetan for prophylaxis rather than treatment; 30% had received cefotetan for < 1 day. Only 18% had prior cefotetan administration. A mean hemoglobin decrease of 6.7 g/dL was noted with a final mean hemoglobin of 5.2 g/dL. Fatalities were reported in 15 cases and renal failure developed in 7 cases. No relationship was found between prior cefotetan use and the development of hemolytic anemia. Patients who receive courses of cefotetan should have periodic monitoring for signs and symptoms of hemolytic anemia including measurement of hematological parameters when appropriate. All cephalosporins may rarely cause hypothrombinemia and have the potential to cause bleeding. Cephalosporins that contain the NMTT side chain (e.g., cefoperazone, cefamandole, cefotetan) have been associated with an increased risk for bleeding. Cefotetan should be used cautiously in patients with a preexisting coagulopathy (e.g., vitamin K deficiency) because these patients are at a higher risk for developing bleeding complications.

A disulfiram-like reaction (flushing, sweating, headache, tachycardia) may occur with ethanol ingestion within 72 hours after cefotetan administration. Counsel patients of appropriate age about avoiding alcohol consumption.

Description: Cefotetan is a parenteral cephamycin antibiotic that is classified as a second-generation cephalosporin. Other second-generation cephamycins include cefoxitin and cefmetazole. Cefotetan differs from most other cephalosporins in its activity against anaerobic organisms, particularly B. fragilis. It also has a somewhat longer half-life, allowing for twice-daily dosing, compared with cefoxitin which requires usual dosing of 4 times daily. Cefotetan is most commonly used in children for intra-abdominal infections and surgical infection prophylaxis. Although not FDA-approved for use in pediatric patients, cefotetan is used off-label in pediatric patients as young as infants.

Per the manufacturer, this drug has been shown to be active against most strains of the following microorganisms either in vitro and/or in clinical infections: Bacteroides fragilis, Bacteroides splanchnicus, Bacteroides vulgatus, Citrobacter freundii, Citrobacter koseri, Citrobacter sp., Clostridium sp., Escherichia coli, Fusobacterium sp., Haemophilus influenzae (beta-lactamase negative), Haemophilus influenzae (beta-lactamase positive), Klebsiella pneumoniae, Klebsiella sp., Moraxella catarrhalis, Morganella morganii, Neisseria gonorrhoeae, Peptococcus niger, Peptostreptococcus sp., Porphyromonas asaccharolytica, Prevotella bivia, Prevotella disiens, Prevotella melaninogenica, Prevotella oralis, Propionibacterium sp., Proteus mirabilis, Proteus vulgaris, Providencia rettgeri, Salmonella sp., Serratia marcescens, Serratia sp., Shigella sp., Staphylococcus aureus (MSSA), Staphylococcus epidermidis, Streptococcus agalactiae (group B streptococci), Streptococcus pneumoniae, Streptococcus pyogenes (group A beta-hemolytic streptococci), Streptococcus sp., Veillonella sp., Yersinia enterocolitica
NOTE: The safety and effectiveness in treating clinical infections due to organisms with in vitro data only have not been established in adequate and well-controlled clinical trials.

For the treatment of intraabdominal infections*, including complicated infections such as peritonitis*, appendicitis*, and intraabdominal abscess*:
Intravenous or Intramuscular dosage:
Infants, Children, and Adolescents: 60 to 100 mg/kg/day (Max: 6 g/day) IV or IM divided every 12 hours. Treat complicated infections with adequate source control for 3 to 7 days. Complicated infections include peritonitis and appendicitis complicated by rupture, and intraabdominal abscess.

For surgical infection prophylaxis*:
Intravenous dosage:
Infants, Children, and Adolescents: 40 mg/kg/dose (Max: 2 g/dose) IV as a single dose within 30 to 60 minutes prior to the surgical incision; consider intraoperative redosing 6 hours from the first preoperative dose. May continue 40 mg/kg/dose (Max: 2 g/dose) IV every 12 hours for no more than 24 hours post-operatively if necessary. Guidelines recommend cefotetan for gastrointestinal procedures, such as colorectal surgery, biliary tract procedures, and appendectomy (nonperforated).

For the treatment of gynecologic infections*, including pelvic inflammatory disease (PID)* and tubo-ovarian abscess*:
-for the general treatment of gynecologic infections*:
Intravenous or Intramuscular dosage:
Adolescents: 30 to 50 mg/kg/dose (Max: 2 g /dose) IV or IM every 12 hours.
-for the treatment of pelvic inflammatory disease (PID)*, including tubo-ovarian abscess*:
Intravenous dosage:
Adolescents: 2 g IV every 12 hours in combination with doxycycline. Cefotetan should be continued for at least 24 to 48 hours after clinical improvement, and then stepdown to oral doxycycline and metronidazole for a total of 14 days of therapy.

Maximum Dosage Limits:
-Neonates
Safety and efficacy have not been established.
-Infants
Safety and efficacy have not been established; doses up to 100 mg/kg/day IV/IM are used off-label.
-Children
Safety and efficacy have not been established; doses up to 100 mg/kg/day IV/IM are used off-label; do not exceed the FDA-approved adult Max of 6 g/day IV; 4 g/day IM.
-Adolescents
Safety and efficacy have not been established; doses up to 100 mg/kg/day IV/IM are used off-label; do not exceed the FDA-approved adult Max of 6 g/day IV; 4 g/day IM.

Patients with Hepatic Impairment Dosing
Specific guidelines for dosage adjustments in hepatic impairment are not available; it appears that no dosage adjustments are needed.

Patients with Renal Impairment Dosing
The following dosage adjustments are based on a usual recommended dose in pediatric patients of 40 to 80 mg/kg/day divided every 12 hours :
CrCl 30 mL/minute/1.73 m2 or more: No dosage adjustment needed.
CrCl 10 to 29 mL/minute/1.73 m2: 20 to 40 mg/kg/dose IV or IM every 24 hours.
CrCl less than 10 mL/minute/1.73 m2: 20 to 40 mg/kg/dose IV or IM every 48 hours.

FDA-approved dosage adjustments in adult patients :
CrCl more than 30 mL/minute: No dosage adjustment needed.
CrCl 10 to 30 mL/minute: Usual dose administered every 24 hours or one-half usual dose every 12 hours.
CrCl less than 10 mL/minute: Usual dose administered every 48 hours or one-quarter usual dose every 12 hours.

Intermittent hemodialysis
20 to 40 mg/kg/dose IV or IM every 48 hours; give on hemodialysis days after dialysis. The FDA-approved recommendation for adult patients is giving one-fourth the usual dose every 24 hours on days between dialysis or one-half the usual dose on the day of dialysis. Alternatively for adults, 1 g IV or IM after dialysis is also recommended.

Peritoneal hemodialysis
20 to 40 mg/kg/dose IV or IM every 48 hours.

Continuous renal replacement therapy (CRRT)
20 to 40 mg/kg/dose IV or IM every 12 hours.

*non-FDA-approved indication

Monograph content under development

Mechanism of Action: Cefotetan is a bactericidal cephamycin antibiotic that inhibits the third and final stage of bacterial cell wall synthesis by preferentially binding to specific penicillin-binding proteins (PBPs) that are located inside the bacterial cell wall. PBPs are responsible for several steps in the synthesis of the cell wall and are found in quantities of several hundred to several thousand molecules per bacterial cell. PBPs vary among different bacterial species. Like all beta-lactam antibiotics, cefotetan's ability to interfere with PBP-mediated cell wall synthesis ultimately leads to cell lysis. Lysis is mediated by bacterial cell wall autolytic enzymes (i.e., autolysins). The relationship between PBPs and autolysins is unclear, but it is possible that the beta-lactam antibiotic interferes with an autolysin inhibitor. Cefotetan has activity in the presence of beta-lactamases, both penicillinases and cephalosporinases, of some gram-negative and gram-positive bacteria.

Beta-lactams, including cefotetan, exhibit concentration-independent or time-dependent killing. In vitro and in vivo animal studies have demonstrated that the major pharmacodynamic parameter that determines efficacy for beta-lactams is the amount of time free (non-protein bound) drug concentrations exceed the minimum inhibitory concentration (MIC) of the organism (free T above the MIC). This microbiological killing pattern is due to the mechanism of action, which is acylation of PBPs. There is a maximum proportion of PBPs that can be acylated; therefore, once maximum acylation has occurred, killing rates cannot increase. Free beta-lactam concentrations do not have to remain above the MIC for the entire dosing interval. The percentage of time required for both bacteriostatic and maximal bactericidal activity is different for the various classes of beta-lactams. Cephalosporins require free drug concentrations to be above the MIC for 35% to 40% of the dosing interval for bacteriostatic activity and 60% to 70% of the dosing interval for bactericidal activity.

The susceptibility interpretive criteria for cefotetan are delineated by pathogen. The MICs are defined for H. influenzae and H. parainfluenzae as susceptible at 4 mcg/mL or less, intermediate at 8 mcg/mL, and resistant at 16 mcg/mL or more. The MICs are defined for Enterobacterales and anaerobes as susceptible at 4 mcg/mL or less, intermediate at 8 mcg/mL, and resistant at 16 mcg/mL or more by the FDA; however, the CLSI definitions are susceptible at 16 mcg/mL or less, intermediate at 32 mcg/mL, and resistant at 64 mcg/mL or more. The MICs are defined for N. gonorrhoeae as susceptible at 4 mcg/mL or less, intermediate at 8 mcg/mL, and resistant at 16 mcg/mL or more by the FDA; however, the CLSI definitions are susceptible at 2 mcg/mL or less, intermediate at 4 mcg/mL, and resistant at 8 mcg/mL or more. Oxacillin-susceptible staphylococci can be considered susceptible to cefotetan. The FDA MIC interpretive criteria are based on a dosing regimen of 2 g IV every 12 hours.

Resistance to cefotetan is primarily through hydrolysis by some beta-lactamases, alteration of PBPs, and decreased drug permeability.

Pharmacokinetics: Cefotetan is administered intramuscularly and intravenously; it is not well absorbed from the GI tract. Approximately 78% to 91% of the circulating drug is protein-bound. It is distributed into many body tissues and fluids including skin, muscle, fat, gallbladder, kidney, bladder, uterus, cervix, ovary, lung, bile as well as peritoneal, pleural, and synovial fluids. It does not reach therapeutic concentrations within the CSF. In adult single-dose trials, the volume of distribution ranged from 7.2 to 16.7 L (weight-based Vd not reported). Cefotetan is not metabolized to a significant degree; it is largely excreted unchanged into the urine via glomerular filtration and tubular secretion. In normal patients, 51% to 81% of a dose is excreted unchanged in the urine within a 24-hour period, which results in high and prolonged urinary concentrations. There is a linear correlation between systemic clearance and CrCl. The elimination half-life is 3 to 4.6 hours in adult patients with normal renal function, which allows for twice-daily dosing.

Affected cytochrome P450 isoenzymes: none


-Route-Specific Pharmacokinetics
Intravenous Route
Peak concentrations (Cmax) are reached immediately after completion of an IV infusion or IV push injection in adults. Cmax has been shown to be higher with IV push administration compared with IV infusion. Cmax values of 55 to 216 mcg/mL are achieved after doses of 10 to 20 mg/kg in children; in adults who received a 2 g dose IV over 3 minutes, the mean plasma concentration 10 minutes after the dose was 223 mcg/ml.

Intramuscular Route
Cefotetan is well absorbed after IM administration. Peak concentrations are reached 1.5 to 3 hours after IM administration. Peak concentrations have been shown to be approximately 25% to 50% lower with IM administration compared with IV administration. The use of lidocaine for IM administration does not affect the pharmacokinetic or pharmacodynamic properties.


-Special Populations
Pediatrics
Children
Limited pharmacokinetic data have shown a slightly shorter elimination half-life (1.85 to 3.5 hours) in pediatric patients compared with adults.

Renal Impairment
Pharmacokinetic data are unavailable in pediatric patients with renal impairment. However, the elimination half-life of cefotetan increases as renal function declines. There is a linear correlation between systemic clearance of cefotetan and creatinine clearance. The mean terminal half-life in adults increases from approximately 4 hours in patients with normal renal function to about 10 hours in those with moderate renal impairment. Cefotetan is removed by hemodialysis.