Open study of low-dose amitriptyline in the treatment of patients with idiopathic fecal incontinence

INTRODUCTION: Amitriptyline, a tricyclic antidepressant agent with antichol inergic and serotoninergic properties, has been used empirically in the tre atment of idiopathic fecal incontinence with good results. METHODS: An open study was conducted to test the response to amitriptyline 20 mg daily for four weeks by 18 patients (2 males) of median age 66 years with idiopathic fecal incontinence. Incontinence scores, number of bowel movements, compute rized ambulatory anorectal pressures, and pudendal nerve terminal motor lat encies were evaluated before and after four weeks of therapy. Twenty-four c ontrol subjects (10 males) of median age 61 years were also assessed. RESUL TS: Amitriptyline improved incontinence scores (median pretreatment score = 16 vs. median posttreatment score = 3; P < 0.001) and reduced the number o f bowel movements per day (P < 0.001). Amitriptyline also decreased the fre quency (median pretreatment frequency = 4.5 per hour vs. median immediate p osttreatment frequency = 1.2 per hour (P < 0.05); control median frequency = 0.3 per hour) and the amplitude of rectal motor complexes (median pretrea tment rectal pressure = 94 cm H2O vs. median immediate posttreatment rectal pressure = 58 cm H2O (P < 0.05); control median rectal pressure = 36 cm H2 O) and improved anal pressures during these events (P < 0.001). CONCLUSIONS : Amitriptyline improved symptoms in 89 percent of patients with fecal inco ntinence. The data support that the major change with amitriptyline is a de crease in the amplitude and frequency of rectal motor complexes. The second conclusion is that drug increases colonic transit time and leads to the fo rmation of a firmer stool that is passed less frequently. These in combinat ion may be the source of the improvement in continence.