Effect of nitrates on LOS pressure in achalasia: a potential therapeutic aid.

The effect of a long-acting nitrate, isosorbide dinitrate (ID) 5 mg sublingually, on the lower oesophageal sphincter was tested in 24 patients with achalasia. The drug caused a reduction in LOS pressure in all cases. The mean LOS pressure fell from 46.32.7 mmHg to 15.31.8 mmHg (p less than 0.01). The pressure began to drop after several minutes, reaching its lowest levels after 15 minutes. This measured manometric effect lasted for 60 minutes or more in 10 patients studied. The reported clinic effect lasted for two to three hours, permitting the ingestion of a meal. Twenty-three patients were followed clinically for two to 19 months while receiving the drug three times daily before meals. Nineteen reported a marked to complete relief of dysphagia. Five of these patients had previous pneumatic dilatation, cardiomyotomy, or both, and had recurrence at time of study. Side-effect, mainly headache, were reported in eight patients. In six this was alleviated by substituting oral isosorbide dinitrate, 10 mg. Two patients became refractory to treatment after two to six months. The potential role of long-acting nitrates in the treatment of achalasia has yet to be established.