Antisecretory activity of opiates in vitro and in vivo in man.

Both in vitro and in vivo studies of the influence of opiates on ion transport and of their antisecretory activity are described. Morphine and the synthetic opioid, loperamide, are included particularly. It is clear that the opiates have an antisecretory effect and can inhibit secretion induced by a variety of different secretagogues. Secretion induced experimentally in the human jejunum in vivo is reduced by loperamide, indicating a potential role for such an agent in the treatment of secretory diarrhoeas.