gastrokinetic drugs /-kinet″ik/ , chemicals that stimulate salivation, increase lower esophageal sphincter pressure, and improve esophageal clearance in the supine, but not in the upright, position. Cisapride, once the widely used drug in this category, has been taken off the market because of fatal arrhythmias. Metoclopramide, another agent in this category, has side effects that make it undesirable, and its efficacy is questionable in comparison to the now widely used proton pump inhibitors.