GASTROINTESTINAL PROKINETIC THERAPY - DOPAMINERGIC ANTAGONIST DRUGS

Motility disorders of the esophagus, stomach, small intestine, and col on are common in dogs and cats. These disorders have usually been trea ted primarily by dietary management and surgical intervention; however , gastrointestinal prokinetic therapy is assuming increasing clinical importance. In parts I through IV of this five-part Continuing Educati on Series, gastrointestinal prokinetic agents are grouped into four ca tegories. For each category of agents, the mechanisms of action, site of activity, and indications for use will be discussed. Part I contain s information about the dopaminergic antagonist drugs, which inhibit p eripheral and/or central dopamine receptors. Metoclopramide and domper idone, for example, reverse the gastric relaxation induced by dopamine infusion in dogs. The agents abolish the vomiting that is associated with apomorphine administration. Part II of the series will deal with motilin-like drugs, Part III will consider serotonergic drugs, as part IV will discuss the acetylcholinesterase inhibitors or parasympatheti c potentiating drugs. The final part will deal with the diagnosis and management of esophageal, gastric, and colonic mobility disorders; cli nical preferences for gastrointestinal prokinetic agents will be highl ighted.