Animal studies have shown that
calcium blocking drugs decrease lower esophageal sphincter pressure and inhibit peristaltic amplitude and duration. In a single-dose acute study, we compared the effects of a new oral
calcium blocker,
diltiazem (90, 120, 150 mg) with placebo in five volunteers and 10 patients with
chest pain/
dysphagia and high amplitude peristaltic contractions in the distal
esophagus--nutcracker esophagus. In volunteers,
diltiazem had no effect on esophageal contractions when compared to baseline values or placebo. In contrast, most doses of
diltiazem significantly (less than 0.05) decreased amplitude and duration of peristaltic contractions in patients with
nutcracker esophagus. Despite adequate blood levels, interstudy analysis was not statistically significant because placebo also decreased these parameters. During an eight-week open-labeled study,
diltiazem 90 mg QID significantly (P less than 0.01) improved symptoms of
chest pain and
dysphagia. Side effects were minimal. Although oral
diltiazem has minimal effect on baseline esophageal contractions, our chronic study suggests it may modify transient increases in neuromuscular tone associated with esophageal
chest pain. These observations warrant further placebo-controlled studies.