Role of a novel antidiarrheal agent, BW942C, alone or in combination with trimethoprim-sulfamethoxazole in the treatment of traveler's diarrhea.

The efficacy of BW942C, a novel enkephalinlike pentapeptide antidiarrheal agent, was compared with the efficacy of trimethoprim-sulfamethoxazole (TMP-SMX) and the combination of the two agents in a placebo-controlled trial of the 72-h treatment of acute diarrhea. Subjects with diarrhea but without bloody stools or fever greater than 102 degrees F (38.9 degrees C) were enrolled. Administered to 134 U.S. adults with diarrhea that developed shortly after their arrival in Guadalajara, Mexico, BW942C was more efficacious than TMP-SMX in relieving diarrhea and cramps in the first 12 h of therapy, especially among subjects with diarrhea caused by enterotoxigenic E. coli. In the BW942C treatment group, 25% of subjects eventually took additional therapy because their diarrhea did not respond to BW942C alone. Neurological side effects such as dizziness and light-headedness occurred more frequently among BW942C-treated subjects. Therapy for 3 days with TMP-SMX provided lasting relief comparable with previously reported 5-day therapy. Use of the combination of both agents provided the benefits of prompt relief afforded by BW942C and lasting relief afforded by TMP-SMX. BW942C might prove to be an agent suitable for the treatment of acute diarrhea, with TMP-SMX reserved for treatment of those who do not respond adequately. The empiric use of the combination of BW942C and TMP-SMX appears appropriate for the treatment of severe nondysenteric disease.