Objective: The study was designed to evaluate the effectiveness of SP-303 (Provir), a plant-derived product with novel antisecretory properties, in the treatment of travelers' diarrhea.
Methods: A total of 184 persons from the United States who acquired diarrhea in Jamaica or Mexico were enrolled in a double-blind, placebo-controlled study examining the effectiveness of three doses of SP-303 in reducing illness. Subjects were treated with 125 mg, 250 mg, or 500 mg SP-303 or a matching placebo four times a day for 2 days. Subjects kept daily diaries of symptoms and were seen each day for 3 days. Of the subjects, 169 (92%) were included in the efficacy analysis.
Results: The most common etiological agent identified was enterotoxigenic Escherichia coli, found in 19% of subjects. The mean time interval from taking the first dose of medication until passage of the last unformed stool during 48 h therapy (TLUS48) was 38.7 h for the placebo group. TLUS48 was shortened by SP-303: 30.6 h for the 125-mg dose group (p = 0.005); 30.3 h for the 250-mg group; and 32.6 h for the 500-mg group (p = 0.01). Treatment failures were seen in 29.3% in the placebo group compared with 7.3% (p = 0.01), 4.3 (p = 0.002), and 9.8 (p = 0.026) in the three treatment groups. SP-303 was well tolerated at all doses.
Conclusions: SP-303 was effective in shortening the duration of travelers' diarrhea by 21%. This antisecretory approach works directly against the pathophysiology of travelers' diarrhea and is not likely to potentiate invasive forms of diarrhea or to produce posttreatment constipation.