Gelatin tannate for treating acute gastroenteritis: a systematic review

Gelatin tannate (GT) is a complex of tannic acid, which possesses astringent, antibacterial, and anti-inflammatory properties, and a protective gelatin. It is increasingly being marketed as an antidiarrheal drug. Our aim was to review data on the effectiveness of GT in treating acute gastroenteritis (AGE) in children and adults. The MEDLINE, EMBASE, and the Cochrane Library databases were searched in July 2013, with no language restrictions, for controlled clinical trials. Additional references were obtained from reviewed articles. Two trials met the inclusion criteria. In adults, one randomized controlled trial involving 40 subjects (mean age: 43±13 years) found that, compared with placebo, GT may be more effective at reducing some symptoms of AGE in the first 48 h after initiation of treatment. In children, one poor quality study (no randomization and no blinding) involving 211 children (mean age: 2.5±2.4 years) reported some beneficial effect of GT at 12 h after initiation of treatment. None of the studies evaluated the effect of GT on the primary outcome measures for this review such as stool output, duration of diarrhea, admission to hospital, duration of hospital stay, and (in children) weight gain after rehydration. Currently, there is no evidence to support the use of GT for treating AGE in children and only sparse evidence to support the use of GT in adults. Further well-designed trials, with sufficient power, adequate follow-up periods, and clinically relevant outcome measures, are needed. These include stool volume, duration of diarrhea, admission to hospital, duration of hospital stay, weight gain after rehydration, and adverse effects.