Ciprofloxacin penetration into human breast milk: a case report

The concentration of ciprofloxacin achieved in human breast milk following oral administration of a single 500-mg dose was investigated. A 24-year-old white woman, 17 days postpartum, was being treated for resolving acute renal failure. Oral ciprofloxacin was prescribed for a suspected urinary tract infection. Due to suspected pediatric toxicity and a lack of published information describing ciprofloxacin excretion in breast milk, the antibiotic was discontinued after one 500-mg dose. All breast milk was collected at four-hour intervals and was tested for the presence of ciprofloxacin by bioassay. Ciprofloxacin breast milk concentrations were 9.1, 9.1, 9.1, and 6.0 mumol/L at 4, 8, 12, and 16 hours postdose, respectively. These ciprofloxacin concentrations were similar to other published body fluid concentrations following a single oral 500-mg dose.