Efficacy of Hyoscine N-butyl Bromide on Cervical Dilatation Prior to Hysteroscopy Procedure: An Open-Label Randomized Controlled Trial.

Abstract

Background: Due to the high prevalence of intrauterine pathologies, postmenopausal women are more eligible for hysteroscopy procedure. Cervical dilatation is always a major challenge for performing hysteroscopy. The present study aimed to determine the efficacy of vaginal Hyoscine N-butylbromide (HBB) on cervical dilatation prior to hysteroscopy in postmenopausal women.

Materials and methods: This open-label randomized controlled trial was conducted on postmenopausal women who were scheduled for hysteroscopy. Eligible patients were randomly assigned with a ratio of 1:1 to the intervention (received 20 mg HBB vaginally two hours prior to hysteroscopy) and control (did not receive HBB) groups. As the study outcomes, pre-hysteroscopy cervical dilatation (based on the passage of the dilator number 4 through the cervical canal) and the adverse event consequences were compared between the two groups.

Results: Overall, 128 postmenopausal women who were eligible for hysteroscopy were included in the study, with 64 individuals in each group. The percentage of cervical dilatation in the intervention group was significantly higher than the control group (100 vs. 70.3%, P<0.001). Furthermore, none of the adverse event consequences differed significantly between the intervention and control groups: bleeding (3.1 vs. 3.1%, P>0.999), nausea and vomiting (4.7 vs. 0%, P=0.244), dry mouth (3.1 vs. 0%, P=0.496), dizziness (0 vs. 0%), and headache (0 vs. 0%).

Conclusion: Based on the findings, vaginal HBB is effective without any significant side effects in cervical dilation of postmenopausal women (registration number: IRCT20220822055772N1).