Treatment of Travelers' Diarrhea: Randomized Trial Comparing Rifaximin, Rifaximin Plus Loperamide, and Loperamide Alone

Background & Aims: Antimotility agents provide rapid temporary relief of acute diarrhea, whereas antibiotics slowly cure the illness. Thus, the combination of an antimotility agent and an antibiotic may provide greater therapeutic benefit than either drug alone. This study evaluated the efficacy and safety of rifaximin-loperamide in the treatment of travelers' diarrhea. Methods: Consenting adults with acute diarrhea (≥3 unformed stools in 24 hours with ≥1 symptom of enteric infection) were randomized to receive rifaximin 200 mg 3 times daily for 3 days; loperamide 4 mg initially followed by 2 mg after each unformed stool; or a combination of both drugs using the same dosing regimen. The primary end point was the median time from beginning therapy until passing the last unformed stool. Results: A total of 310 patients completed treatment with rifaximin (n = 102), loperamide (n = 104), or rifaximin-loperamide combination therapy (n = 104). The groups showed demographic similarity. Rifaximin and rifaximin-loperamide significantly reduced the median time until passage of the last unformed stool (32.5 ± 4.14 h and 27.3 ± 4.13 h, respectively) vs loperamide (69 ± 4.11 h; P = .0019). The mean number of unformed stools passed during illness was lower with rifaximin-loperamide (3.99 ± 4.28) compared with rifaximin (6.23 ± 6.90; P = .004) or loperamide alone (6.72 ± 6.93; P = .002). All treatments were well tolerated with a low incidence of adverse events. Conclusions: Rifaximin-loperamide therapy provided rapid symptomatic improvement and greater overall wellness compared with either agent alone.