Objective: To evaluate levofloxacin secretion in human breast milk.
Methods: Breast milk was collected from a lactating woman during a 23-day period in which she received levofloxacin 500 mg/day and for 5 days after discontinuation of levofloxacin. The levofloxacin concentration was assayed by high-performance liquid chromatography. A two-compartment pharmacokinetic model was used to estimate peak and total levofloxacin exposure.
Results: At steady state, peak levofloxacin exposure in breast milk was 8.2 microg/ml at 5 hours after dosing. Elimination pharmacokinetics followed the anticipated pattern.
Conclusion: Peak levofloxacin concentration in human breast milk is similar to levels attained in plasma. However, breast-feeding mothers who take levofloxacin will expose their infants to levofloxacin in concentrations below those being studied in the pediatric population.