CEFMETAZOLE

Fetal Risk Summary

Cefmetazole is an injectable, second-generation cephalosporin antibiotic. Structurally it is similar to cefamandole (N-methylthiotetrazole side chain) and may cause similar adverse effects (hypoprothrombinemia and bleeding, and a disulfiram-like reaction with alcohol) (1).

Shepard reviewed three reproduction studies that had been conducted in pregnant rats and dogs (2). No adverse effects or teratogenicity were observed when the antibiotic was administered during organogenesis or other stages of gestation.

It is not known if cefmetazole crosses the human placenta. The molecular weight (about 494 for the sodium salt) is low enough that transfer to the fetus should be expected.

Although no published reports on the use of cefmetazole during human pregnancy have been located, cephalosporin antibiotics are usually considered safe to use during gestation.

Breast Feeding Summary

No published reports describing the use of cefmetazole in human lactation have been located. The molecular weight (about 494 for the sodium salt) is low enough that excretion into breast milk should be expected. If excretion does occur, three potential problems exist for the nursing infant: modification of bowel flora, direct effects on the infant, and interference with the interpretation of culture results if a fever workup is required. The American Academy of Pediatrics considers other cephalosporins to be compatible with breast feeding (3).

References

1. Reynolds JEF, editor. Martindale. The Extra Pharmacopoeia. 31st ed. London, England:Royal Pharmaceutical Society, 1996:187.
2. Shepard TH. Catalog of Teratogenic Agents. 9th ed. Baltimore, MD:The Johns Hopkins University Press, 1998:85.
3. Committee on Drugs, American Academy of Pediatrics. The transfer of drugs and other chemicals into human milk. Pediatrics 1994;93:137–50.