A final case seriesadministered ciprofloxacin 750 mg, pefloxacin 400 mg, or ofloxacin 400 mg twice daily to 3 groups of 10 women each.5 Milk samples were obtained 6 times over 24 hours following the third dose of antibiotic. Maximum levels in breast milk occurred 2 hours after the dose, and were 3.79, 3.54, and 2.41 mcg/mL for ciprofloxacin, pefloxacin, and ofloxacin respectively. All 3 quinolones achieved higher concentrations in breast milk than in serum.
But are these drugs safe for children?
While TMP/SMX and nitrofurantoin are generally considered safe when given to infants and children (barring G6PD deficiency), data are mixed regarding the safety of quinolones. Ciprofloxacin’s FDA indication for pediatric patients is limited to postexposure anthrax prophylaxis due to evidence of fluoroquinolone-induced joint toxicity in animal studies.6 Despite this, they have been prescribed to tens of thousands of children for select scenarios such as chemotherapy-induced immuno-compromise, cystic fibrosis, complicated UTIs, and salmonella infections.7
A report was published summarizing safety data from the Bayer database of compassionate use of ciprofloxacin.8 The report indicates that 2030 treatment courses of ciprofloxacin were given to 1795 children up to age 17 for a variety of infections; only 3% were under age 5. Most patients received 21 to 40 mg/kg of ciprofloxacin per day; treatment duration was from 1 to 303 days. Arthralgia occurred in 1.5% of patients, most of whom had cystic fibrosis. Of the 31 patients affected, arthralgias resolved in 25, improved in 1, and remained unchanged in 1. (Data regarding resolution were unavailable for 4 patients.)
Recommendations from others
The American Academy of Pediatrics’ Committee on Drugsconsiders the following antibiotics typically used for UTI to be compatible with breastfeeding: ciprofloxacin, ofloxacin, nitrofurantoin (caution for infants with G6PD deficiency), and TMP/SMX.9
Drugs in Pregnancy and Lactation considers trimethoprim and sulfamethoxazole to be compatible with breastfeeding but cautions against sulfamethoxazole use in infants with known G6PD deficiency. The authors categorize nitrofurantoin, ciprofloxacin, and ofloxacin as “probably compatible/limited human data,” and advise caution with nitrofurantoin for infants with G6PD deficiency.10