Efficacy of Loperamide for C. Difficile Colitis and Other Diarrheal Diseases Associated With Antibiotic Therapy

Colitis due to Clostridium difficile has been increasingly recognized as a serious nosocomial problem. Recommended therapy is with metronidazole, 500 mg four times daily for 10 days. About 80% of patients respond to this therapy. However, the response may be be delayed, in which case debilitation due to diarrhea progresses. The 20% who do not respond tend to be sicker to start, and debilitation due to diarrhea is a severe problem. In reviewing the medical literature, we discovered that the earliest papers on C. difficile colitis emphasized symptomatic therapy with 'lomotil' (diphenoxylate with atropine). Treatment to suppress the diarrhea fell out of favor in the late 1970's because of the theoretical consideration that it was better to expel than to retain the bacterial toxins. However, the patients who are affected by C. difficile colitis are increasingly elderly and debilitated, and suffer substantial morbidity from the diarrhea. We have shown that the 90-day associated mortality is \>20%. Loperamide is a standard treatment for diarrhea, and is available over the counter under the name, Imodium. Based on a few anecdotal reports, this drug is regarded as contraindicated in patients whose diarrheal disease is bacterial. But it is used widely, and generally without any diagnosis being established. We now propose to administer loperamide or placebo to patients with CDAD in order to determine whether the antidiarrheal drug reduces morbidity associated with the infection. We will monitor our patients closely both to observe potential benefits and/or adverse events. In the addendum, we propose to include patients who have antibiotic-associated diarrheal disease that is not due to C. difficile. There are many patients who have antibiotic-associated diarrheal disease who test negative for C. difficile. We believe that these patient may benefit from loperamide treatment as well.