Background: Antidepressant agents may have a therapeutic role in functional gastroenterologic disorders, but controlled investigations in irritable bowel syndrome (IBS) have not provided satisfactory practice recommendations. To help with future study design, we reviewed a five-year clinical experience with antidepressant agents in out-patients with IBS. Methods: Presenting features, treatment course, and clinical outcome were determined from a chart review of 138 patients attending a university-based gastroenterology practice.
Results: Patients were treated with up to five antidepressants in separate, consecutive trials if a satisfactory end-point had not been reached. Tricyclic antidepressants were utilized 130 times, newer antidepressants 39 times, and anxiolytic-antidepressants 47 times. Improvement and complete remission in bowel symptoms occurred in 89% and 61% of patients, respectively, during antidepressant therapy. Median dosages being prescribed when remission occurred were less than those conventionally used in clinical psychiatry (50 mg/day for several tricyclic antidepressants). Age, gender, symptom duration, and presence of psychological symptoms did not discriminate those who remitted from those who did not, whereas a pain predominant symptom pattern was more commonly associated with symptom remission (P < 0.05 comparing symptom patterns). Symptom remission was more likely during the first antidepressant treatment than with subsequent trials in the group with continued symptoms (P = 0.01), but nearly half of the patients with side effects or no benefit from the first agent who went on to subsequent trials remitted during treatment with an alternative antidepressant.
Conclusions: The design of this retrospective review is not capable of determining the efficacy of antidepressants for IBS. Our observations in conjunction with other available data suggest that future trials should employ low daily dosages, carefully assess pain response, include patients with and without active psychiatric symptoms, and utilize a second agent for subjects intolerant or unresponsive to the first.