Effect of hyoscine butyl-bromide on the duration of active phase of labor: A randomized-controlled trial

Hyoscine butyl bromide (HBB) is known for its antispasmodic action and has been in use for over five decades, there is however no consensus on its effectiveness in the labor process. The aim of this study was to determine the effect of HBB on the duration of the active phase of labor.

A randomized double-blind placebo-controlled clinical trial involving 160 parturient who received either intravenous Hyoscine butyl-bromide (20 mg in 1 ml; n = 80) or intravenous normal saline (1 ml, n = 80). The mean duration of active phase of labor was compared between the two groups.

The observed mean duration of the active phase of labor was significantly shorter (P = 0.001) in the Hyoscine butyl-bromide group (365.11 ± 37.32 min, range = 280-490) than in the Placebo group (388.46 ± 51.65 min, range = 280-525). There was no significant difference between the two groups in the mean duration of the second and third stages of labor (20.46 ± 10.46 vs. 23.38 ± 18.95 min, P = 0.43 and 8.96 ± 4.34 vs. 9.23 ± 5.92 min, P = 0.75, respectively). The mean 1-min APGAR scores were also comparable (8.08 ± 1.54 vs. 7.64 ± 1.60, P = 0.08). The mean postpartum blood loss was significantly less in the Hyoscine butyl-bromide group (303 ± 96.52 vs. 368 ± 264.19 ml, P = 0.04).

Hyoscine butyl-bromide was effective in shortening the duration of the active phase of labor. It was also associated with significantly less postpartum blood loss.