The present invention relates to smooth muscle spasmolytic agents, pharmaceutical compositions containing them and method of using said compounds and compositions for the treatment of urinary incontinence, and other smooth muscle contractility conditions. More particularly, the present invention relates to certain metabolically stabilized secondary amines having smooth muscle relaxing properties while avoiding, on administration to a mammal, adverse side effects such as prominent antimuscarinic, arrhythmogenic and cardiodepressive effects.