The effect of an octapeptide somatostatin analogue (SMS 201-995) and somatostatin-14 (SST-14) on pentagastrin-stimulated gastric acid secretion: a comparative study in man.
Using an open, randomised study design, the efficacy and tolerance of SMS 201-995 (a synthetic octapeptide SST-14 analogue with a plasma half-life of 45 min) was compared with that of SST-14 in inhibiting pentagastrin-stimulated gastric acid secretion. In 10 healthy volunteers gastric acid secretion was stimulated for 3.5 hours by an infusion of 3 microgram kg-1 h-1 pentagastrin. One hour after the start of pentagastrin a 2-hour i.v. infusion of either SST-14 (3.5 microgram kg-1 h-1) or one of 4 dosages of SMS 201-995 (0.14, 0.28, 0.56 or 1.12 microgram kg-1 h-1) was started. SMS 201-995 inhibited acid secretion in a dose-dependent manner. The inhibition achieved with the 0.56 and 1.12 microgram kg-1 h-1 dosages was comparable with that obtained with 3.5 microgram kg-1 h-1 SST-14. SMS 201-995 (1.12 microgram kg-1 h-1) appeared to have a longer duration of action than SST-14. No side effects were recorded under either of the test substances.