Transfer of celecoxib into human milk.

The aim of this study was to investigate the transfer of celecoxib into human milk. In one group of 3 breastfeeding patients on celecoxib at steady state, milk levels were determined at set intervals over 24 hours. Plasma levels were determined in 2 of their infants, age 17 and 22 months. In a second group of 2 subjects, intravenous lines were placed and a single 200-mg dose of celecoxib was followed by multiple paired plasma and milk samples over 8 hours. The mean milk-to-plasma ratio for celecoxib was 0.23 (95% confidence interval [CI]: 0.15-0.31). The average concentration of celecoxib in milk during the 8-hour dosing interval was 66 microg/L (95% CI: 41-89). The absolute infant dose averaged 9.8 microg/kg/d (95% CI: 6.2-13.4); the mean relative infant dose was 0.30%. Therefore, the average clinical dose transferred to the infant daily would be approximately 0.3% of the weight-adjusted maternal dose. The authors suggest that the use of celecoxib in breastfeeding mothers at these doses is very unlikely to cause untoward effects in breastfed infants.