Anidulafungin Levels in Breast Milk After Cessation of Treatment: A Case Report

Anidulafungin has poor oral bioavailability, with hardly any available information on how it affects breast milk, oral absorption, or gastrointestinal side effects in the infant. A 40-year-old woman who recently gave birth to a healthy infant was treated for a period of 14 days for a Candida glabrata with 100 mg anidulafungin once a day. The department of clinical pharmacy was consulted to provide advice on how long the patient had to wait after ceasing anidulafungin before it was safe to start breastfeeding, with regard to preventing possible side effects of the drug to the infant, such as diarrhea or cholestasis and increase in liver enzyme values. The advice of the hospital pharmacist was pragmatic: to start breastfeeding within 2 days after the medication was discontinued based on half-time. Owing to this lack of information, we measured anidulafungin concentrations in breast milk and found low levels. We concluded that anidulafungin is detectable in breast milk until 32 hours after anidulafungin treatment was stopped, and that no side effects were observed by the infant.