Amounts of tinidazole in milk are less than doses given to infants. Measurements of infant plasma levels during breastfeeding have not been reported. No studies have evaluated adverse effects of tinidazole on the infant during breastfeeding, but presumably they are similar to those of the closely related drug, metronidazole, such as increased risk of oral and rectal Candida infections.
As with metronidazole, concern has been raised about exposure of healthy infants to tinidazole via breastmilk,[1] because of possible mutagenicity and carcinogenicity. Opinions vary among experts on the advisability of using tinidazole during longer-term therapy while breastfeeding, but avoidance of breastfeeding for 3 days after a single dose should allow milk levels to drop to negligible values.[2] Other drugs are available for bacterial vaginosis, and can be given vaginally, which should result in lower amounts in breastmilk.