The main criteria to be considered for releasing an antidiarrhoeal from a prescription to an OTC-drug are guaranteed quality control, established efficacy and safety and the evaluation of the drug experience on major markets. Besides the considerable benefits from a socio-economic point of view, the risk for potential inappropriate use of loperamide (CAS 53179-11-6) as self-medication can be minimized by its use being avoided in children of 5 years of age or less (e.g. by making available a solid formulation only), by limiting the treatment duration to 48 h, and by contraindicating the use of the drug in cases of fever (> 38 degrees C) and/or blood in the stools. On the basis of a broad review loperamide can be considered to be efficacious in acute non-specific, acute functional and traveller's diarrhoea. The agent has a good safety profile if the mentioned restrictions are born in mind. Loperamide thus satisfies the OTC criteria.