Aim: Our aim was to compare the efficacy and tolerability of loperamide and racecadotril in elderly patients with acute diarrhea.
Research design and methods: We performed a randomized, prospective, double-blind, and parallel group design implemented in geriatric nursing homes in Catanzaro, Italy, from February 2008 to March 2009. Patients of both sexes were randomly allocated to receive either one tablet of racecadotril 100 mg every 8 h or two tablets of loperamide 2.0 mg followed by one tablet after each unformed stool, up to four tablets in any 24-h period. Patients were treated until recovery, defined as the production of two consecutive normal stools or no stool production for a period of 12 h.
Results: Normal stools were collected 36 +/- 4 h after the beginning of racecadotril and in 63 +/- 6 h from the beginning of loperamide administration (P < 0.01). The median time of abdominal pain in the intent-to-treat (ITT) population was 14 h for racecadotril and 28 h for loperamide. In the per-protocol (PP) population, the median time of abdominal pain was 14 h for racecadotril and 32 h for loperamide (P < 0.01). About the 50% of patients experienced at least one adverse event during the study: 12% in the racecadotril group and 60% in the loperamide group. The most frequently occurring adverse events were nausea and constipation. Genetic analysis did not report the presence of rapid or poor metabolizers. Pharmacoeconomic analysis performed at the end of our study documented an increase in costs in the loperamide group with respect to the racecadotril group (P < 0.01).
Conclusions: Racecadotril is more effective than loperamide-probably due to drug interaction with loperamide-and it is not related to pharmacogenetic susceptibility. Racecadotril is also more cost effective than loperamide.