No information provided.
General: METROGEL® Topical Gel has been reported to cause tearing
of the eyes. Therefore, contact with the eyes should be avoided. If a reaction
suggesting local irritation occurs, patients should be directed to use the medication
less frequently or discontinue use. Metronidazole is a nitroimidazole and should
be used with care in patients with evidence of, or history of blood dyscrasia.
Carcinogenesis, mutagenesis, impairment of fertility
Metronidazole has shown evidence of carcinogenic activity in a number of studies involving chronic, oral administration in mice and rats but not in studies involving hamsters.
Metronidazole has shown evidence of mutagenic activity in several in vitro
bacterial assay systems. In addition, a dose-response increase in the frequency
of micronuclei was observed in mice after intraperitoneal injections and an
increase in chromosome aberrations have been reported in patients with Crohn's
disease who were treated with 200-1200 mg/day of metronidazole for 1 to 24 months.
However, no excess chromosomal aberrations in circulating human lymphocytes
have been observed in patients treated for 8 months.
Teratogenic effects: Pregnancy category B:
There has been no experience to date with the use of METROGEL® (metronidazole
topical gel) Topical Gel in pregnant patients. Metronidazole crosses the placental
barrier and enters the fetal circulation rapidly. No fetotoxicity was observed
after oral metronida-zole in rats or mice. However, because animal reproduction
studies are not always predictive of human response and since oral metron-idazole
has been shown to be a carcinogen in some rodents, this drug should be used
during pregnancy only if clearly needed.
After oral administration, metronidazole is secreted in breast milk in concentrations
similar to those found in the plasma. Even though METROGEL® Topical Gel
blood levels are significantly lower than those achieved after oral metronidazole,
a decision should be made whether to discontinue nursing or to discontinue the
drug, taking into account the importance of the drug to the mother.
Safety and effectiveness in pediatric patients have not been established.