<qa>  What is the semisynthetic derivative of scopolamine?The safety of active management of labor has been demonstrated by several prospective randomized clinical trials. A shorter duration of labor from admission to delivery has also been consistently reported in numerous studies of women treated with the active management protocol.Hyoscine butylbromide belongs to the parasympatholytic group of drugs and is a semisynthetic derivative of scopolamine. It is an effective antispasmodic drug without the untoward side effects of atropine. Hyoscine butylbromide is a quaternary ammonium compound and has peripheral anticholinergic action, but no central action as it does not cross the blood-brain barrier. Hyoscine butylbromide acts primarily by blocking the transmission of neural impulses in the intraneural parasympathetic ganglia of abdominal organs, apparently inhibiting cholinergic transmission in the synapses of the abdominal and pelvic parasympathetic ganglia, thus relieving spasms in the smooth muscles of gastrointestinal, biliary, urinary tract, and female genital organs, especially the cervico-uterine plexus, thus aiding cervical dilatation. 