Double-blind comparison of intravenous butorphanol (Stadol) and fentanyl (Sublimaze) for analgesia during labor

Abstract

Objective: Our purpose was to compare the analgesic properties, effect on labor, and maternal-fetal side effects of intravenous butorphanol and fentanyl.

Study design: One hundred patients with uncomplicated term pregnancies were enrolled during early active labor. Each patient received standard doses of either fentanyl (50 to 100 micrograms) or butorphanol (1 to 2 mg) hourly on request in a double-blind manner. Pain was scored independently by the nurse and patient with a 10-point visual analog scale. Categoric and measurement data were collected for comparison of the effects on uterine activity, maternal and fetal well-being, and neonatal outcomes.

Results: The fentanyl (n = 50) and butorphanol (n = 50) groups were identical with respect to maternal age, race, parity, and weight. Greater improvement in pain relief was found after the first dose of butorphanol than after fentanyl (p < 0.05). When fentanyl was given, either more doses were necessary (3.2 +/- 1.3 vs 2.1 +/- 1.1, p < 0.01) or epidural analgesia was requested more often (16%, 32% vs 9%, 18%, p < 0.05). Uterine contraction patterns for the first hour after dosing were unchanged, and the duration of the first and second stages of labor were not different between the two groups. No differences in maternal or newborn adverse effects were observed.

Conclusions: Both drugs were equally safe and without effect on active labor. Butorphanol provided better initial analgesia than fentanyl with fewer patient requests for more medication or epidural analgesia.