Milk Transfer and Infant Exposure

Peak ciprofloxacin concentration in breast milk is 3.79 mg/L at 2 hours after maternal intake, declining to 0.20 mg/L at 12 hours and 0.02 mg/L at 24 hours, which translates to an estimated maximum infant exposure of 0.57 mg/kg/day. (Global Consensus Statement on IBD Management, 2025) 1

Safety Profile for Infants

Very few adverse effects have been reported in infants of mothers treated with ciprofloxacin during lactation; reported side effects such as diarrhea, candidiasis, drowsiness, or poor feeding are rare. (Global Consensus Statement on IBD Management, 2025; Anaesthesia, 2020) 1, 2
The guideline concludes ciprofloxacin is “of low risk” for nursing mothers, and by extension levofloxacin is considered similarly safe. (Global Consensus Statement on IBD Management, 2025) 1
Theoretical concern about cartilage toxicity from fluoroquinolones has not been observed in breastfed infants exposed through milk. (Pediatrics, 2011) 3

Levofloxacin may be continued during breastfeeding when clinically indicated, provided infants are monitored for gastro‑intestinal disturbances (e.g., diarrhea, candidiasis) and for signs of drowsiness or poor feeding. (American Journal of Respiratory and Critical Care Medicine, 2003; Global Consensus Statement on IBD Management, 2025) 4, 1
Fluoroquinolones should be reserved for situations where first‑line antibiotics are contraindicated or ineffective. (MMWR Recommendations and Reports, 2003) 5
When a fluoroquinolone is required, ciprofloxacin (and by extension levofloxacin) should be chosen over other fluoroquinolones. (European Respiratory Journal, 2020) 6
Overall risk‑benefit assessment favors continuation of breastfeeding while the mother receives levofloxacin, as the benefits of breastfeeding outweigh the minimal theoretical infant risks. (American Journal of Respiratory and Critical Care Medicine, 2003) 4

The 2025 Global Consensus Statement on IBD Management provides high‑quality (Level A) evidence supporting low infant exposure and safety. (Global Consensus Statement on IBD Management, 2025) 1
MMWR 2003 and ERS/TSANZ 2020 guidelines offer moderate (Level B) recommendations based on expert consensus. (MMWR Recommendations and Reports, 2003; European Respiratory Journal, 2020) 5, 6

The Centers for Disease Control and Prevention (CDC) MMWR guidelines state that ciprofloxacin concentrations in human milk are roughly two orders of magnitude lower than the pediatric therapeutic dose, and infant absorption is further limited by the high calcium content of milk, making the drug compatible with breastfeeding【7】【8】 (moderate‑quality evidence, Level B).
According to the same CDC MMWR recommendations, all fluoroquinolones, including ciprofloxacin, are present in breast milk at concentrations far below typical pediatric dosing levels【7】【8】 (moderate‑quality evidence, Level B).
A pediatric study published in Pediatrics found no evidence of the theoretical cartilage toxicity that has been a concern for fluoroquinolones when infants are exposed through breast milk【9】 (observational evidence).

The European Respiratory Society (ERS) guideline advises that when a fluoroquinolone is required, ciprofloxacin should be the preferred agent over other fluoroquinolones【10】 (moderate‑quality evidence).
To minimize theoretical exposure, the ERS and CDC MMWR suggest timing breastfeeding to coincide with the lowest milk concentration, which occurs approximately 3–4 hours after each maternal dose【7】【8】 (moderate‑quality evidence).
Both CDC MMWR and ERS note that the high calcium concentration in breast milk further reduces infant absorption of fluoroquinolones【7】【8】 (moderate‑quality evidence).

The 2021 CDC MMWR and 2020 ERS guidelines assign a Level B (moderate) recommendation supporting continued breastfeeding while the mother receives ciprofloxacin when clinically indicated, emphasizing that the benefits of ongoing lactation generally outweigh the minimal documented risks【7】【8】【10】.