The sphincter of Oddi is the smooth muscle connection between the bile duct and 
the duodenum. Its physiological function is associated with a regular motility 
characterized by phasic contractions superimposed on the sphincter of Oddi 
baseline pressure. Recently introduced ERCP-manometry permits further studies of 
sphincter of Oddi pharmacology. A number of drugs have so far been studied. 
Sedatives of the diazepam type had no effect on the sphincter, while 
butylscopolaminium bromide, a typical neurotropic agent, brings about cessation 
of the sphincter motility for 3-8 minutes. Hymecromon lowered the sphincter 
baseline pressure from 9.8 to 7.8 mmHg. A 1.2 mg sublingual dose of 
nitroglycerin, a typical musculotropic agent, caused significant relaxation of 
the sphincter, and decreased baseline pressure from 8.9 mmHg to 2.9 mmHg; 
Sphincter motility was not affected. Morphine-like analgetics, in particular 
pentazocine, elevated sphincter baseline pressure, but buprenorphine and 
tramadol did not. Pharmacological doses of gastrointestinal hormones also affect 
the sphincter; CCK octapeptide, glucagon and secretin are able to decrease 
sphincter of Oddi baseline pressure, and CCK octapeptide abolishes sphincter 
motility. Sphincter of Oddi pharmacology is of clinical interest. The 
administration of sphincter-relaxing agents, in particular nitroglycerin and 
butylscopolaminium bromide, enables the endoscopist to extract small common bile 
duct stones without previous papillotomy. Analgetics that induce sphincter 
contraction and thus hinder the flow of bile and pancreatic juice, may be 
helpful for the treatment of pain in patients with pancreatico-biliary disease. 
Investigations into the effect of CCK on the healthy and diseased sphincter 
permit us to identify patients with sphincter dysfunction using a special 
CCK-provocation test.