Pharmaniaga Metronidazole Use In Pregnancy & Lactation

Pregnancy: Metronidazole crosses the placenta and enters the foetal circulation rapidly. Adequate and well-controlled studies in humans have not been done. Studies in rats, given doses of up to 5 times the human dose, have not shown that metronidazole causes impaired fertility or birth defects in the foetus. Metronidazole, administered intraperitoneally to pregnant mice at approximately the human dose, has been shown to cause foetotoxicity. When administered orally, no foetotoxicity was seen in pregnant mice (FDA Pregnancy Category B). However, the use of metronidazole in the treatment of trichomoniasis is contraindicated during the first trimester. If metronidazole is used during the second and third trimester for trichomoniasis, it is recommended that its use be limited to those patients whose symptoms are not controlled by local palliative treatment. Also, the 1-day course of therapy should not be used since this results in higher maternal and foetal serum concentrations.
Breast-feeding: Metronidazole is distributed into breast milk; concentrations are similar to those found in the maternal plasma. Use is not recommended in nursing mothers since some studies in rats and mice have shown that metronidazole is carcinogenic and may cause adverse effects in the infant. However, use in the treatment of anaerobic bacterial infections or a short course of treatment with metronidazole for amoebiasis, severe periodontal infections, or trichomoniasis may be necessary in nursing mothers. During treatment with metronidazole the breast milk should be expressed and discarded. Breast-feeding may be resumed 24 and 48 hours after treatment is completed.