Carbenicillin

Pregnancy Category B.

Reproduction studies have been performed at dose levels of 1000 or 500 mg/kg in rats, 200 mg/kg in mice, and at 500 mg/kg in monkeys with no harm to fetus due to carbenicillin. There are, however, no adequate and well controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

Labor and Delivery

It is not known whether the use of carbenicillin in humans during labor or delivery has immediate or delayed adverse effects on the fetus, prolongs the duration of labor, or increases the likelihood that forceps delivery or other obstetrical intervention or resuscitation of the newborn will be necessary.

Carbenicillin class antibiotics are excreted in milk although the amounts excreted are unknown; therefore, caution should be exercised if administered to a nursing woman.

There are no long-term animal or human studies to evaluate carcinogenic potential. Rats fed 250–1000 mg/kg/day for 18 months developed mild liver pathology (e.g., bile duct hyperplasia) at all dose levels, but there was no evidence of drug-related neoplasia. Carbenicillin administered at daily doses ranging to 1000 mg/kg had no apparent effect on the fertility or reproductive performance of rats.

The following adverse reactions have been reported as possibly related to carbenicillin administration in controlled studies which include 344 patients receiving carbenicillin.

Gastrointestinal: The most frequent adverse reactions associated with carbenicillin therapy are related to the gastrointestinal tract. Nausea, bad taste, diarrhea, vomiting, flatulence, and glossitis were reported. Abdominal cramps, dry mouth, furry tongue, rectal bleeding, anorexia, and unspecified epigastric distress were rarely reported.

Dermatologic: Hypersensitivity reactions such as skin rash, urticaria, and less frequently pruritus.

Hematologic: As with other penicillins, anemia, thrombocytopenia, leukopenia, neutropenia, and eosinophilia have infrequently been observed. The clinical significance of these abnormalities is not known.

Miscellaneous: Other reactions rarely reported were hyperthermia, headache, itchy eyes, vaginitis, and loose stools.

Abnormalities of Hepatic Function Tests: Mild SGOT elevations have been observed following carbenicillin administration.