Wood
creosote, the principal ingredient in
Seirogan, has a long history as a known gastrointestinal microbicidal agent. When administered orally, the intraluminal concentration of wood
creosote is not sufficiently high to achieve this microbicidal effect. Through further animal tests, we have shown that antimotility and antisecretory actions are the principal
antidiarrheal effects of wood
creosote. Wood
creosote inhibits intestinal secretion induced by
enterotoxins by blocking the Cl(-) channel on the intestinal epithelium. Wood
creosote also decreases intestinal motility accelerated by mechanical, chemical, or electrical stimulus by the inhibition of the Ca(2+) influx into the smooth muscle cells. In this overview, the antimotility and antisecretory effects of wood
creosote are compared with those of
loperamide. Wood
creosote was observed to inhibit stimulated colonic motility, but not normal jejunal motility.
Loperamide inhibits normal jejunal motility, but not stimulated colonic motility. Both wood
creosote and
loperamide inhibit intestinal secretion accelerated by
acetylcholine. Wood
creosote was found to have greater antisecretory effects in the colon than
loperamide. Based upon these findings, we conclude that the
antidiarrheal effects of wood
creosote are due to both antisecretory activity in the intestine and antimotility in the colon, but not due to the microbicidal activity as previously thought. Wood
creosote was found to have no effects on normal intestinal activity. These conclusions are supported by the results of a recent clinical study comparing wood
creosote and
loperamide, which concluded that wood
creosote was more efficacious in relieving
abdominal pain and comparable to
loperamide in relieving
diarrhea.