Objective: To estimate the extent of passage of hydrocodone and its active metabolite, hydromorphone, into breast milk.
Methods: This is a pharmacokinetic study of 30 postpartum women receiving hydrocodone bitartrate for postpartum pain in the inpatient setting. Mothers donated timed breast milk samples for the analysis of hydrocodone and hydromorphone.
Results: Fully breastfed neonates received 1.6% (range 0.2%-9%) of the maternal weight-adjusted hydrocodone bitartrate dosage. When combined with hydromorphone, the total median opiate dosage from breast milk is 0.7% of a therapeutic dosage for older infants. Most mothers excreted little to no hydromorphone into breast milk.
Conclusion: Standard postpartum dosages of hydrocodone bitartrate appear to be acceptable to use in women nursing newborns. Prolonged use of high dosages is not advisable.