Cefoxitin and Dextrose (Page 4 of 6)

7.1 Aminoglycosides

Increased nephrotoxicity has been reported following concomitant administration of cephalosporins and aminoglycoside antibacterials.

8 USE IN SPECIFIC POPULATIONS

8.1 Pregnancy

Risk Summary

Available data from published prospective cohort studies, case series, and case reports over several decades with cephalosporin use, including cefoxitin, in pregnant women have not established drug-associated risks of major birth defects, miscarriage, or adverse maternal or fetal outcomes (see Data). In animal reproduction studies, no adverse developmental effects were observed in pregnant rats and mice administered parenteral doses of cefoxitin at approximately 1 to 7.5 times the maximum recommended human dose (see Data).

The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. Cefoxitin is found in umbilical cord blood and amniotic fluid after maternal administration.

Clinical Considerations

Disease-Associated Maternal and/or Embryo/Fetal Risk

Maternal gonorrhea may be associated with preterm birth, low neonatal birth weight, chorioamnionitis, intrauterine growth restriction, small for gestational age and premature rupture of membranes. Perinatal transmission of gonorrhea to the offspring can result in infant blindness, joint infections and bloodstream infections.

Data

Human Data

While available studies cannot definitively establish the absence of risk, published data from prospective cohort studies, case series, and case reports over several decades have not identified an association with cephalosporin use, including cefoxitin, during pregnancy, and major birth defects, miscarriage, or other adverse maternal or fetal outcomes.

Available studies have methodologic limitations, including small sample size, retrospective data collection, and inconsistent comparator groups.

Animal Data

Reproduction studies performed in pregnant rats and mice at parenteral doses of approximately one to seven and one-half times the maximum recommended human dose did not reveal teratogenic or fetal toxic effects, although a slight decrease in fetal weight was observed.

In the rabbit, cefoxitin was associated with a high incidence of abortion and maternal death. This was not considered to be a teratogenic effect but an expected consequence of the rabbit’s unusual sensitivity to antibiotic-induced changes in the population of the microflora of the intestine.

8.2 Lactation

Risk Summary

Limited data from published literature report the presence of cefoxitin in human milk. For an infant fed exclusively with human milk, the estimated infant daily dose through breastfeeding is less than 0.1% of maternal daily IV dose (see Data). Minimal data are available on the effects of the drug on the breastfed infant; none of these reports suggest serious safety concerns. No data are available on the effects of the drug on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for cefoxitin and any potential adverse effects on the breastfed infant from cefoxitin or from the underlying maternal condition.

Data

In a published clinical lactation study, the concentration of cefoxitin ranged from 11.6 ± 0.8 to 0.49 ± 0.01 mcg/mL and 1.71 ± 0.08 to 0.57 ± 0.02 mcg/mL in human plasma and breast milk, respectively, at 1, 1.5, 2 or 2.5 hours following IV administration of 1 g cefoxitin twice daily.

8.4 Pediatric Use

Safety and efficacy of this formulation are not established. This formulation of cefoxitin is indicated for use only in patients who require the entire 1 or 2 gram dose.

8.5 Geriatric Use

Of the 1,775 subjects who received cefoxitin in clinical studies, 424 (24%) were 65 and over, while 124 (7%) were 75 and over. No overall differences in safety or effectiveness were observed between these subjects and younger subjects, and other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out [see Clinical Pharmacology (12.3 )].

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 [ seeDosage and Administration (2.3), and Clinical Pharmacology (12.3)].

8.6 Renal Impairment

In patients with a reduced creatinine clearance the dose of Cefoxitin Injection and Dextrose Injection should be adjusted to compensate for the slower rate of renal elimination. Because high and prolonged cefoxitin concentrations can occur from usual dosages in patients with renal impairment or other conditions that may compromise renal function, the maintenance dosage should be reduced when Cefoxitin Injection and Dextrose Injection is administered to such patients. Continued dosage should be determined by the degree of renal impairment, severity of infection, and susceptibility of the causative organisms [see Dosage and Administration (2.3)].

10 OVERDOSAGE

Information on overdosage with Cefoxitin for Injection and Dextrose Injection in humans is not available. If overdosage should occur, it should be treated symptomatically.

11 DESCRIPTION

Cefoxitin for Injection and Dextrose Injection is a sterile, nonpyrogenic, single-dose packaged combination of cefoxitin sodium USP and Dextrose Injection (diluent) in the DUPLEX^® sterile container. The DUPLEX^® Container is a flexible dual chamber container.

The drug chamber is filled with cefoxitin sodium USP, a semi-synthetic, broad-spectrum cephalosporin antibacterial sealed under nitrogen for intravenous administration. Cefoxitin sodium USP is derived from cephamycin C, which is produced by Streptomyces lactamdurans. Its chemical name is sodium (6R ,7S)-3-(hydroxymethyl)-7-methoxy-8-oxo-7-[2-(2-thienyl)acetamido]-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate carbamate (ester).

The empirical formula is C₁₆ H₁₆ N₃ NaO₇ S₂ , and the molecular weight is 449.44. The structural formula is:

Cefoxitin sodium contains approximately 53.8 mg (2.3 mEq) of sodium per gram of cefoxitin activity.

The diluent chamber contains Dextrose Injection. The concentration of Dextrose Hydrous USP in Water for Injection USP has been adjusted to render the reconstituted drug product iso-osmotic. Dextrose Hydrous USP has been added to adjust the osmolality to approximately 290 mOsmol/kg (approximately 2 g (4% w/v) and 1.1 g (2.2% w/v) to the 1 g and 2 g doses, respectively). Dextrose Injection is sterile, nonpyrogenic, and contains no bacteriostatic and antimicrobial agents.

Dextrose Hydrous USP has the following structural (molecular) formula:

The molecular weight of Dextrose Hydrous USP is 198.17.

After removing the peelable foil strip, activating the seals, and thoroughly mixing, the reconstituted drug product is intended for single intravenous use. When reconstituted according to instructions in the product labeling, the approximate osmolality of the reconstituted solution of Cefoxitin for Injection and Dextrose Injection is approximately 290 mOsmol/kg. After reconstitution, each 50 mL contains 1 gram of cefoxitin (equivalent to 1.05 gram of cefoxitin sodium) or 2 grams of cefoxitin (equivalent to 2.10 grams of cefoxitin sodium), with a pH of approximately 6.5. Solutions of Cefoxitin for Injection and Dextrose Injection range from colorless to light amber.

The DUPLEX® dual chamber container is made from a specially formulated material. The product (diluent and drug) contact layer is a mixture of thermoplastic rubber and a polypropylene ethylene copolymer that contains no plasticizers. The safety of the container system is supported by USP biological evaluation procedures.