Factor causing relaxation of LES Factor increasing LES pressure Pharmacological agents:nitrates, anticholinergics, barbiturates, calcium channel blockers, caffeine, theophylline, diazepam, dopamine, prostaglandin E1 and E2 and meperidine Pepperdine Chocolate Coffee Alcohol Smoking Fat Antacids Cholinergics Domperidone Metoclopramide Prostaglandin F2 Also know: LES pressure is higher in the supine position than in the upright position. Ref: Schwarz 9/e, Page 812; Harrison 17/e, Page 1741.