Medicamentous obstetric analgesia with pentazocine in comparison with an untreated control group

: In order to establish whether a powerful analgesic such as pentazocine administered during birth may damage the child or have negative influence on the course of birth, the course of delivery was studied in 40 patients, 20 of whom were given a single dose of 30 mg pentazocine administered intramuscularly. There were no differences in duration of birth, CTG, blood gases post partum, or Apgar scores as compared to the untreated control group. As regards the pharmacokinetics, the serum pentazocine levels of the gravidae corresponded to those found in non-pregnant subjects; the levels found in blood from umbilical cords and new-borns were at the lower limit of detectability. Almost all of the gravidae described the obstetric analgesia as good or adequate. The principal side effect, mentioned by one-third of the pentazocine group, was slight fatigue. As regards the newborns, the fetal outcome in the two groups was the same.