Antidiarrheal effects of L-histidine-supplemented rice-based oral rehydration solution in the treatment of male adults with severe cholera in Bangladesh: A double-blind, randomized trial

Background. Because of the antisecretory potential of L-histidine in the intestinal tract, its antidiarrheal effects were determined in cholera. Methods. In a double-blind trial of 126 adult male patients with cholera, L-histidine (2.5 g/L) was mixed with a rice-based oral rehydration solution (ORS) and administered to 62 patients; 64 patients received the same ORS without L-histidine. All patients received ciprofloxacin at a dosage of 500 mg every 12 h for 72 h. Fluid output (of stool, urine, and vomit) and intake (of ORS, water, and intravenous fluid) were determined every 8 h for 72 h. Results. Administration of ORS with L-histidine significantly (P<.05) reduced the frequency of stool output during 32-64 h after initiation of ORS treatment, compared with that in patients given ORS without L-histidine ([all data are means ± SD] 32-48 h, 11.5 ± 6.9 mL/kg vs. 18.8 ± 16.0 mL/kg; 40-48 h, 6.7 ± 4.4 mL/kg vs. 11.5 ± 9.7 mL/kg; and 56-64 h, 6.3 ± 5.8 mL/kg vs. 7.8 ± 4.1 mL/kg). An overall reduction of 22% in the volume of stool was observed in patients given ORS without L-histidine. The amount of required unscheduled intravenous fluid was lower in patients given ORS with L-histidine, compared with that in patients given ORS without L-histidine (0-24 h, 82.5 ± 44.4 mL/kg vs. 158.6 ± 72.2 mL/kg [P<.01]; and 24-48 h, 41.6 ± 40.4 mL/kg vs. 52.5 ± 22.1 mL/kg [P>.05]). Administration of ORS with L-histidine also significantly reduced (P<.05) the intake of ORS and the duration of illness. No adverse effects were observed in these patients. Conclusions. L-histidine reduces the weight of stool and the frequency of stool output in cholera and could be a useful and safe adjunct treatment that will increase the success rate of ORS and antibiotic therapy in cholera.