Objective: To compare the safety and efficacy of loperamide plus ciprofloxacin with those of ciprofloxacin alone in the treatment of bacillary dysentery.
Design: Double-blind, placebo-controlled, randomized clinical trial.
Setting: Hospital in Thailand.
Participants: Eighty-eight adults with dysentery seeking medical care between November 1990 and February 1992. Patients who had received prior antibiotics or antimotility drugs were excluded.
Intervention: All 88 patients with dysentery were treated with ciprofloxacin, 500 mg twice daily for 3 days. Forty-two of these patients were randomly assigned to receive loperamide, a 4-mg initial dose followed by 2 mg after every loose stool (as many as eight caplets [16 mg] daily), and 46 were randomly assigned to receive placebo.
Measurements: Stools were collected daily until resolution of diarrhea and again after 10 days. The time to passage of the last unformed stool, number of unformed stools, and symptoms were recorded after treatment.
Results: Shigella or enteroinvasive Escherichia coli (53%), Vibrio parahaemolyticus (16%), and Salmonella (7%) were the most common bacterial enteric pathogens identified in 88 patients with dysentery. In patients infected with Shigella or enteroinvasive E. coli, the median duration of diarrhea was 19 hours (25th to 75th percentiles, 6 to 42 hours) for those receiving loperamide plus ciprofloxacin compared with 42 hours (21 to 46 hours) for those receiving ciprofloxacin alone (P = 0.028). The median number of diarrheal stools for those receiving ciprofloxacin and loperamide was 2.0 (1 to 5 stools) compared with 6.5 (2 to 9 stools) for those receiving ciprofloxacin alone (P = 0.016). None of the participants had a temperature greater than 38 degrees C after 24 hours of treatment. None of the patients was infected with the same bacterial enteric pathogen more than 1 day after receiving treatment.
Conclusions: Loperamide decreases the number of unformed stools and shortens the duration of diarrhea in dysentery caused by Shigella in adults treated with ciprofloxacin.