USEFULNESS AND SAFETY OF PIRENZEPINE IN DOUBLE-CONTRAST STUDY OF UPPER GASTROINTESTINAL-TRACT - COMPARISON WITH SCOPOLAMINE METHYLBROMIDE

To evaluate usefulness of pirenzepine, a selective M1 antimuscarinic d rug, for diagnostic double-contrast study of the upper gastrointestina l tract, pirenzepine and scopolamine methylbromide (SMB) were compared in a single blind randomized trial. Seventy consecutive patients were enrolled in the study. Artifacts, bowel distention, painting of stoma ch and duodenal bulb, and global quality of the images were blindly ev aluated by four independent observers by means of a numerical score (1 -4). Under SMB slightly but significantly better results for stomach w ere scored (3.1 +/- .7 vs. 2.7 +/- 7, p < 0.01). No differences were f ound in the study of the duodenal bulb. Heart rate and rhythm during t he study were recorded by electrocardiogram (ECG). SMB induced tachyca rdia in all patients (from 77 +/- 20 to 117 +/- 28 beats/min, p < 0.01 ) while pirenzepine did not (from 77 +/- 16 to 81 +/- 23, p = NS). Aft er SMB, two-patients exhibited faintness, and some patients complained of visual accommodation defects, dryness of the mouth, and dizziness. Thus, pirenzepine provides good results in double-contrast studies (e qual to SMB), while presenting no adverse effects. It could be propose d as a first choice hypotonic agent in upper gastrointestinal examinat ion.