Loperamide-simethicone vs loperamide alone, simethicone alone, and placebo in the treatment of acute diarrhea with gas-related abdominal discomfort. A randomized controlled trial.

Author(s): Kaplan MA, Prior MJ, Ash RR, McKonly KI, Helzner EC, Nelson EB

Affiliation(s): Medical Department, McNeil Consumer Healthcare, Fort Washington, Pa., USA. mkaplan@mccus.jnj.com

Publication date & source: 1999-05, Arch Fam Med., 8(3):243-8.

Publication type: Clinical Trial; Randomized Controlled Trial

CONTEXT: Acute diarrhea with gas-related abdominal discomfort is a common, usually self-limited disorder with substantial social and economic impact. OBJECTIVE: To compare the efficacy and safety of a loperamide hydrochloride-simethicone combination product with those of loperamide alone, simethicone alone, and placebo in treating acute diarrhea with gas-related abdominal discomfort. DESIGN: Randomized, placebo-controlled, double-blind trial of 48 hours' duration. SETTING: A primary care, ambulatory practice in Acapulco, Mexico. PATIENTS: A total of 493 outpatient adults aged 18 to 63 years, with acute nonspecific diarrhea with at least moderately severe abdominal discomfort. INTERVENTIONS: Each patient was randomly assigned to receive 2 chewable tablets containing loperamide hydrochloride, 2 mg, and simethicone, 125 mg (n = 124); loperamide hydrochloride, 2 mg (n = 123); simethicone, 125 mg (n = 123); or placebo (n = 123). This was followed by 1 tablet after each unformed stool, up to 4 tablets in any 24-hour period. MAIN OUTCOME MEASURES: Time to last unformed stool and time to complete relief of gas-related abdominal discomfort were the protocol-specified primary outcomes. Secondary outcomes included time to complete relief of diarrhea, number of unformed stools, and patient-assessed variables at the end of the study (overall illness relief, diarrhea relief, and abdominal discomfort relief). RESULTS: Patients who received loperamide-simethicone had significantly (P < .001) shorter time to last unformed stool and faster relief of gas-related abdominal discomfort than patients who received loperamide, simethicone, or placebo alone. Loperamide-simethicone was significantly (P < or = .01) more effective than the other 3 treatments for all end-of-study patient-assessed outcomes and all clinically important secondary outcomes. No significant differences in adverse events were found among treatment groups. CONCLUSIONS: The loperamide-simethicone combination chewable product provides faster and more complete relief of acute nonspecific diarrhea and associated gas-related abdominal discomfort (gas pain, cramps, gas pressure, and bloating) than either of its components or placebo. The combination is well tolerated.