[Elimination of nalbuphine in human milk].

In order to examine the pharmacokinetics and excretion of nalbuphine (Nubain 20) in breast milk, patients suffering from postpartum pain were given a single dose of 20 mg nalbuphine intramuscularly. During a 24-h period, the total amount of nalbuphine excreted in the breast milk was 2.3 micrograms (mean value), which is equivalent to 0.012% of the dosage. The mean milk/plasma quotient was calculated using the AUC from the milk and plasma time curves at 1.2:1. An oral intake of 2.3 micrograms nalbuphine would not show any measurable plasma concentrations in the neonate. Adverse opioid reactions, e.g. respiratory depression are not to be expected even if one assumes a lack of glucuronide production in the neonate.