Tinidazole and Breastfeeding

Summary of use during lactation

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.

Drug levels in milk and infant serum

Maternal Levels. Three women were given tinidazole 150 orally twice daily starting on day 4 postpartum. On day 7, milk samples were collected at 2, 5 and 9 hours after a dose. Breastmilk concentrations ranged between 5.8 and 12.7 mg/L.[3] Twenty-four women who delivered by cesarean section were given a single intravenous dose of tinidazole 500 mg after cord clamping. Colostrum levels of tinidazole averaged 5.8 mg/L at 12 hours after the dose, 3.5 mg/L at 24 hours, 1.2 mg/L at 48 hours and 0.3 mg/L at 72 hours after the dose. The drug was barely detectable 96 hours after the dose. Only slight differences existed between concentrations in fore- and hindmilk.[4] Five women who delivered by cesarean section were given a single intravenous dose of tinidazole 1600 mg after cord clamping. Milk concentrations and volumes were measured for 96 hours after the dose. The authors concluded that milk concentrations would be sufficiently low to commence breastfeeding 72 hours after the dose.[2] Infant Levels. Relevant published information was not found as of the revision date.

Effects in breastfed infants

Relevant published information was not found as of the revision date.

Effects on lactation and breastmilk

Relevant published information was not found as of the revision date.

Alternative drugs to consider

(Anaerobic bacterial infections) Amoxicillin and Clavulanic Acid, Clindamycin, Doxycycline; (Bacterial Vaginosis) Clindamycin, Metronidazole; (Giardiasis) Metronidazole

References

1. American Academy of Pediatrics Committee on Drugs The transfer of drugs and other chemicals into human milk. Pediatrics 2001 108 776 89 11533352 PubMed
2. EvaldsonGR LindgrenS NordCE Tinidazole milk excretion and pharmacokinetics in lactating women. Br J Clin Pharmacol 1985 19 503 7 4039599 PubMed
3. WoodBA FaulknerJK MonroAM The pharmacokinetics, metabolism and tissue distribution of tinidazole. J Antimicrob Chemother 1982 10 Suppl A 43 57 7118775 PubMed
4. MännistöPT KarhunenM KoskelaO Concentrations of tinidazole in breast milk. Acta Pharmacol Toxicol (Copenh) 1983 53 254 6 6356785 PubMed