About Camylofin dihydrochloride Synthetic anticholinergic, direct smooth muscle relaxant. Mechanism of Action of Camylofin dihydrochloride Camylofin dihydrochloride is a potent antispasmodic and is useful in active phase of labor. It accelerates the rate of cervical dilatation and shortens the duration of active phase of first stage of labor significantly without any undesirable effects on the fetus. It has no effect on the second and third stage of labor and no effect on uterine activity.