Metronidazole and pregnancy.

Pregnancy Category B. Metronidazole crosses the placental barrier and enters the fetal circulation rapidly. Reproduction studies have been performed in rats at doses up to five times the human dose and have revealed no evidence of impaired fertility or harm to the fetus due to metronidazole.

Metronidazole should be used during pregnancy only if it is clearly needed.

In pregnant patients in whom alternative treatment has been inadequate, the one-day course of therapy should not be used, as it results in higher serum levels which can reach the fetal circulation.

Do not use Metronidazole if you are allergic to metronidazole, or if you are in the first trimester of pregnancy.

Metronidazole appears in breast milk and could affect a nursing infant.

Tell your doctor if you are pregnant before using this drug. It should not be used during the first 3 months of pregnancy and used only with caution during the last 6 months, unless your infection has not improved on other antibiotics.

No fetotoxicity was observed when metronidazole was administered orally to pregnant mice at 20 mg/kg/day, approximately one and a half times the most frequently recommended human dose (750 mg/day) based on mg/kg body weight; however in a single small study where the drug was administered intraperitoneally, some intrauterine deaths were observed. The relationship of these findings to the drug is unknown.

Metronidazole should not be used during the first 3 months of pregnancy to treat vaginal infections. Do not take Flagyl if you have ever had an allergic reaction to or are sensitive to metronidazole or similar drugs.

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

The effects of Metronidazole in pregnancy have not been adequately studied.

There are, however, no adequate and well-controlled studies in pregnant women.
Because animal reproduction studies are not always predictive of human response, and because metronidazole is a carcinogen in rodents, this drug should be used during pregnancy only if clearly needed.

Tell your doctor about any drug reactions you have experienced.

The safety of this medicine during pregnancy has not been fully established. It should only be used during pregnancy if considered essential by your doctor because no safer antibiotics are suitable or available. High dosage regimens should be avoided. Seek medical advice from your doctor.

Use of Flagyl for trichomoniasis during pregnancy should be restricted to those in whom alternative treatment has been inadequate. Use of Metronidazole for trichomoniasis in pregnancy should be carefully evaluated because metronidazole crosses the placental barrier and its effects on the human fetal organogenesis are not known.

Pregnant patients should not be treated during the first trimester.

If Metronidazole is essential to your health, your doctor may advise you to stop breastfeeding until your treatment is finished.

Tell your doctor if you are pregnant or plan to become pregnant during treatment.

Metronidazole is not used in early pregnancy because of potential adverse effects on the fetus.