What can be concluded from a clinical trial that spanned 5 years yet failed to achieve target enrollment, generated flat results that contradict the existing body of knowledge and has a primary efficacy endpoint confounded by a treatment-by-COVID interaction? Could it be a false negative finding?

This is a case study of a 76-year-old female patient, who was admitted to our ward with complaints of diarrhea, abdominal pain and weight loss of five kilograms over the past month. This case contains three topics of interest. Firstly, the problem with frequent use of commercial drug names making it difficult for patients and treating physicians to identify those drugs for what they are, and thus enabling possible side-effects. Secondly, a topic worthy of attention is the existence of many over the counter drugs, some of which, like salicylates, have many possible side-effects, which compel reliance on patients to intelligently use available over the counter drugs. As this case demonstrates, such reliance does not always prove to be appropriate. The third issue to be addressed is that pepto-bismuth subsalycilate contains a salycilate moiety. Manufacture's instructions call for abstinence from this drug with known allergy to aspirin. However, given the different capabilities of salycilates, and the relative safety attributed to this drug, the salycilate moiety in peptobismuth subsalycilate does not always receive sufficient attention by both patients and physicians.

An open-label, parallel comparison of loperamide hydrochloride (Imodium A-D) and bismuth subsalicylate (Pepto-Bismol) was conducted using nonprescription dosages in adult students with acute diarrhea (three or more unformed stools in the preceding 24 hours plus at least one additional symptom of enteric infection). For the two-day study period, the daily dosage was limited to 8 mg (40 ml) for loperamide-treated subjects and to 4.9 g for bismuth subsalicylate-treated subjects. At these dosages, loperamide significantly reduced the average number of unformed bowel movements relative to bismuth subsalicylate. Following the initial dose of treatment, control of diarrhea was maintained significantly longer with loperamide than with bismuth subsalicylate. Time to last unformed stool was significantly shorter with loperamide than with bismuth subsalicylate. In providing overall subjective relief, subjects rated loperamide significantly better than bismuth subsalicylate at the end of the 24 hours. Both treatments were well tolerated, and none of the minor adverse effects reported resulted in discontinuation of therapy. It was concluded that loperamide is effective at a daily dosage limit of 8 mg (40 ml) for the treatment of acute nonspecific diarrhea and provides faster, more effective relief than bismuth subsalicylate.

Stools collected from 39 infants and children with chronic nonspecific diarrhea and from 10 age-matched controls were examined for bile acid content with use of gas-liquid chromatography. Values were correlated with stool color. Mean concentration of bile acids in green stools (7.7 +/- 1.52 mg/g dry weight) was significantly higher than that in brown stools (3.76 +/- 0.7 mg/g dry weight) and in control stools (1.42 +/- 0.35 mg/g dry weight). In patients with green diarrhea, treatments with cholestyramine and bismuth subsalicylate (Pepto-Bismol) were equally effective in decreasing stool frequency, with the latter being more effective in decreasing water content. Patients with brown stools had an insignificant response to therapy.