Studies on the kinetics and distribution of dihydralazine in pregnancy.

Plasma kinetics of dihydralazine (50 mg p.o.) was studied in 11 women in late pregnancy. The distribution pattern between maternal and umbilical plasma was investigated in 12 patients who received 75-100 mg dihydralazine per day. In one patient amniotic fluid concentration and in another breast milk levels could be evaluated twice. Plasma concentrations of dihydralazine were very low. Continuous plasma level curves could be estimated in only four of the examined patients. In every case dihydralazine concentrations were higher in umbilical blood than in maternal plasma. Concentrations found in breast milk were clinically negligible.