Concentrations of Cis(Z)-flupentixol in maternal serum, amniotic fluid, umbilical cord serum, and milk.

A venous blood sample and an umbilical cord blood sample were obtained from five young women treated with the neuroleptic drug, cis(Z)-flupentixol decanoate in Viscoleo (intramuscularly) or flupentixol (orally) at the time of giving birth. In two cases amniotic fluid was also obtained, and from three of the mothers milk and simultaneous blood samples were obtained in the lactation period. Concentrations of the active drug, cis(Z)-flupentixol were measured in serum, amniotic fluid, and milk by radioimmunoassay. It was found that the concentration of the active drug in umbilical cord serum (fetal serum) was lower than that in serum from the mother--the ratio being about 0.24. Thus the amounts of drug reaching the fetus are low, but they cannot be considered unimportant. The concentrations found in milk were about 30% higher than the serum concentrations. However, the amounts of drug administered to the neonate with the milk are very low and, unless the neonate differs considerably from the adult as to sensitivity to or metabolism of this particular drug, they are of no importance.