Is Diflucan (fluconazole) safe to use during breastfeeding?

Fluconazole (Diflucan) Safety During Breastfeeding

Fluconazole (Diflucan) is generally considered compatible with breastfeeding and can be safely used by nursing mothers. 1, 2

Evidence on Fluconazole in Breast Milk

Fluconazole passes into breast milk in relatively low concentrations. According to the FDA drug label:

• After a single 150 mg dose, the estimated daily infant dose from breast milk is approximately 0.39 mg/kg/day
• This represents about 13% of the recommended pediatric dose for oropharyngeal candidiasis
• The drug appears in breast milk with peak concentrations of 2.61 mcg/mL (range: 1.57-3.65 mcg/mL) at about 5.2 hours post-dose 1

Clinical Experience and Safety Data

The safety profile of fluconazole during breastfeeding is supported by several important findings:

• A published survey of 96 breastfeeding women treated with fluconazole 150 mg every other day (average of 7.3 capsules, range 1-29 capsules) for lactation-associated candida reported no serious adverse reactions in infants 1, 3
• Fluconazole is routinely used in the treatment of fungal diseases in infants directly and has a good safety profile 2
• The European Respiratory Society/TSANZ guidelines classify fluconazole as "compatible" with breastfeeding 4

Dosing Considerations

For treatment of breast and nipple thrush in breastfeeding women:

• Most women require more than the standard three 150 mg capsules
• The average number of capsules needed is 7.3 (median = 6)
• Women with more severe breast pain typically require more capsules 3
• Only minor side effects have been reported even with extended treatment courses 3

Important Considerations

1. No need to interrupt breastfeeding: Current evidence indicates there is no need to interrupt or suspend breastfeeding when a mother is being treated with fluconazole 2

2. Monitoring: While no serious adverse effects have been reported, it's prudent to monitor the infant for any unusual symptoms during maternal treatment

3. Pregnancy warning: Note that fluconazole has different safety considerations during pregnancy (particularly at higher doses) than during breastfeeding 1

Clinical Application

For treatment of persistent breast and nipple thrush:

• Initial loading dose of 400 mg followed by 100 mg twice daily for at least 2 weeks can be used while continuing to breastfeed 2
• Alternative regimen: 150 mg capsule every other day until resolution of symptoms (typically 6 capsules, but may require more for severe cases) 3

Fluconazole is particularly valuable for treating ductal candidiasis that doesn't respond to topical antifungal treatments, as it can reach the deeper breast tissue through systemic distribution 5.