[Obstetrical analgesia with tramadol--results of a prospective randomized comparative study with pethidine].

Morphine derivatives are the most frequently used analgetic substances in obstetrics today. Nevertheless, nausea, vomiting, weariness, and somnolence are common side effects of these drugs. Moreover opiates exhibit a depressive effect on ventilatory activity. As many studies have demonstrated tramadol, a new analgetic substance amongst the opiates does not show a depressive effect to such a high degree. In this prospective randomized trial we compared the efficacy as well as the safety of 100 mg tramadol and 100 mg pethidine in 40 women asking for pain relief during labour. The duration of labour was slightly but not statistical significantly shorter in the pethidine group. An analgetic effect could be observed in the pethidine as well as the tramadol group by both the pregnant women and the attending physician about 10 min after application lasting for about 2 hours. Concerning the side effects tramadol highly contrasted with pethidine. There were less cases of weariness and somnolence and the ventilatory frequency of the newborn babies tended to be higher than in the pethidine group. The serum levels of tramadol in umbilical and maternal veins demonstrated values of 0.83 +/- 0.15 (mean +/- SEM; quotient). The results of this study seem to establish an analgetic effect of tramadol similar to pethidine but with less side effects.