Famotidine, a new H2-receptor antagonist. Effect on parietal, nonparietal, and pepsin secretion in man.
We studied pentagastrin-stimulated acid and pepsin secretion with three doses (5, 10, and 20 mg) of a new H2-receptor antagonist (famotidine) administered orally to normal male volunteers. A dose response was identified: 2 hr after oral dosing, 5 mg famotidine suppressed stimulated acid secretion to 60% of control and was comparable to 300 mg cimetidine (55% suppression). Higher doses of famotidine yielded significantly more suppression of acid secretion (10 mg yielding 70% and 20 mg, 90%). Pentagastrin-stimulated acid secretion remained decreased (50% of control) 12 hr after oral dosing with 20 mg famotidine. The reduction in pepsin output paralleled the reduction in acid secretion and was primarily due to a reduction in the volume of secretion and not to a change in pepsin concentration. We calculated the components of gastric secretion (acid from parietal cells) and bicarbonate secretion (from nonparietal cells) and found that the primary effect of the H2-receptor antagonists was a dramatic reduction in parietal cell output without a significant decrease in nonparietal secretion. Famotidine proved to be a potent inhibitor of both the parietal component of gastric acid and pepsin output. Famotidine was significantly more potent than cimetidine; 5 mg of famotidine was comparable to 300 mg of cimetidine.
Smith
J L
JL
Gamal
M A
MA
Chremos
A N
AN
Graham
D Y
DY
D000328:Adult; D002927:Cimetidine / Q000494:pharmacology; D015738:Famotidine; D005745:Gastric Acidity Determination; D005750:Gastric Juice / Q000378:metabolism*; D006635:Histamine H2 Antagonists / Q000494:pharmacology*; D006801:Humans; D008297:Male; D010295:Parietal Cells, Gastric / Q000187:drug effects / Q000378:metabolism*; D010418:Pentagastrin; D010434:Pepsin A / Q000378:metabolism*; D013844:Thiazoles / Q000494:pharmacology*; D013997:Time Factors
D006635:Histamine H2 Antagonists; D013844:Thiazoles; D015738:Famotidine; D002927:Cimetidine; D010434:Pepsin A; D010418:Pentagastrin