Compounds represented by the following general formula:wherein Ag is an optionally substituted 5- to 14-membered heterocyclic group, etc. Medications in a flexible bag of the container are expelled from the bag by the pump into an administration set and delivered to an infusion site. The compounds are also useful for the treatment of substance abuse disorders, the treatment of obesity or eating disorders, as well as the treatment of asthma, constipation, chronic intestinal pseudo-obstruction, and cirrhosis of the liver.