[Excretion of pethidine in mother's milk (author's transl)].

Each of nine nursing mothers received one single intramuscular injection of 50 mg pethidine (Dolcontral), between the third and eighth days from childbirth. The highest pethidine concentration, 0.526 mumol/l or 0.13 microgrms/ml, was recorded from breast milk, two hours from application. After 24 hours, the concentration had dropped to 0.081 mumol/l or 0.02 microgram/ml. - The milk-serum quotient was in excess of 1.0. A correlation was found to exist between pethidine concentrations in the serum, on the one hand, and those in mother's milk, on the other. - One single application of Dolcontral is not expected to be of harmful effect on the newborn.