The effect of hyoscine butylbromide on the duration and progress of labor in primigravidae: a randomized controlled trial.

OBJECTIVE: To assess the effect of hyoscine butylbromide (HBB) on duration of the first stage of labor in primigravdae.

METHODS: A case-control study conducted on 120 primigravida at term admitted in active labor were divided into three equal groups. A single dose of the drug (placebo or HBB 20 mg or HBB 40 mg) was injected intravenously slowly to groups A, B, and C. The duration of the first stage was calculated from the time of cervical dilatation of three to four centimeters in active labor until a fully dilated cervix was observed.

RESULTS: The duration of first stage was significantly shorter in women receiving 20 and 40 mg of HBB when controlled to control women (187.73 ± 20.92, 186.41 ± 19.40 versus 231.39 ± 33.14 min). There was no significant difference between the three study groups regarding duration of the second stage (36.76 ± 9.98, 35.72 ± 9.97 and 37.55 ± 10.57, respectively, p > .05), number of cases delivered by cesarean section (12.5%, 12.5%, and 15%, respectively, p > .05) and Apgar score of the neonates (p > .05). There was no significant difference between the three study groups regarding occurrence of side effects named dry mouth (7.5%, 12.5%, and 5%, p > .05), flushing (2.5%, 5% and 0%, p > .05), tachycardia (2.5%, 2.5%, and 2.5%, p > .05), or urinary retention (2.5%, 0%, and 0%, p > .05).

CONCLUSION: Intravenous injection of HBB decreases the duration of active phase of labor in primigravidae with no side effects.