Calcium channel blockers and motility disorders of the esophagus.

In animal experiments, esophageal smooth muscle, including the lower esophageal sphincter (LES) has been shown to be dependent on extracellular calcium both for tone and agonist induced contractions. Calcium channel blockers (CCB) suppress contractile activity, and block both resting and stimulated calcium influx. In normal man as well as in patients with hypercontractility disorders of the esophagus, such as achalasia and diffuse esophageal spasm, CCBs have been shown to reduce LES pressure and esophageal contractions, and also to cause symptomatic improvement. Controlled clinical trials on their effectiveness are lacking, but the therapeutic principle seems promising.