Propiomazine hydrochloride in obstetrical analgesia. A controlled study of 520 patients.

This controlled, double-blind clinical trial was designed to compare the effectiveness of meperidine alone and meperidine combined with either promethazine or propiomazine in obstetrical analgesia. A statistical method for randomization was used to divide 520 women in labor into 3 treatment groups. Neither the patient nor the examining physician knew which of the 3 drug combinations was being given. It was found that the use of either promethazine or propiomazine in conjunction with meperidine contributed to a calmer, more comfortable labor and a more easily managed patient. No statistically significant difference was found, however, between the effects of these 2 tranquilizers. There was no evidence that either compound potentiated the analgesic effect of meperidine.