Racecadotril (acetorphan) is an oral enkephalinase inhibitor for use in the treatment of acute diarrhoea. By preventing the degradation of endogenous enkephalins, racecadotril reduces hypersecretion of water and electrolytes into the intestinal lumen. Treatment with racecadotril reduces the incidence and duration of acute diarrhoea and reduces diarrhoea-associated symptoms compared with placebo in adults. Racecadotril treatment also results in significant reductions in stool output compared with placebo in infants and young children aged 2 months to 4 years with acute diarrhoea. Both rotavirus-negative and rotavirus-positive infections appear to respond to treatment in the paediatric populations investigated for this infection.
Racecadotril shows similar or slightly reduced efficacy to loperamide in the treatment of diarrhoea in adults and children aged up to 10 years. However, in comparative trials racecadotril was associated with fewer adverse events than loperamide, in particular post-treatment constipation.
Racecadotril has been well tolerated in all age groups evaluated showing an adverse event profile similar to placebo.
Oral rehydration therapy is the mainstay of treatment for infants and children with diarrhoea in developing countries, for all elderly patients with diarrhoea and for patients with dehydrating diarrhoea. The introduction of oral rehydration therapy programmes in developing countries, where children under 5 years of age are at the greatest risk of dying from diarrhoea, has resulted in significant reductions in diarrhoea-related mortality. However, oral rehydration therapy does not offer rapid relief of diarrhoeal symptoms which can lead to the inappropriate use of antimicrobial agents with the consequent risk of developing antimicrobial resistance. Furthermore, antimotility agents such as loperamide which are effective in adults, are not indicated for use in very young children.
In industrialised countries, symptomatic therapy of acute diarrhoea can help older children and adults return to normal daily activities more quickly and improve quality of life for travellers. Loperamide is a highly effective drug for the treatment of acute diarrhoea in such circumstances. However, it may result in post-treatment constipation and on rare occasions it will worsen certain forms of invasive bacterial diarrhoea.