Abstract
Summary The comparative actions of two benzamides; the one metoclopramide, having and the other, BRL 20627, lacking dopamine receptor antagonist properties have been investigated on orocaecal transit time (OCTT) using the lactulose/breath hydrogen method. In addition, the action of codeine, propantheline and domperidone on OCTT has been assessed. Similar quantitative reductions in apparent OCTT were found with metoclopramide and BRL 20627 thus, metoclopramide 20 mg orally and 10 mg i.v. brought about 32.5% and 42% reductions in OCTT. Similar reductions were also found using 20 mg BRL 20627 orally and 10 mg i.v. (31 and 26% respectively). In addition 20 mg domperidone orally was found to cause a 10% reduction. Codeine orally and propantheline i.m. brought about increases in the assessed transit time.