Twenty four hour intragastric acidity and plasma gastrin concentration in healthy volunteers taking nizatidine 150 mg, nizatidine 300 mg, ranitidine 300 mg, or placebo at 21:00 h.

Nine healthy volunteers were studied on the seventh day of dosing at 21:00 h with nizatidine 150 mg (N 150), nizatidine 300 mg (N 300), ranitidine 300 mg (R 300), or placebo, given in a predetermined random order. The double-blind 24 hour studies, using the Royal Free Hospital standard protocol, simultaneously measured intragastric acidity and plasma gastrin concentration. Compared with placebo, subjects responded to dosing with each H2-antagonist by a significant decrease of 24 hour intragastric acidity (N 150-45%; N 300-49% R 300-56%; p less than 0.01) and a significant rise of plasma gastrin concentration (N 150 + 20%; N 300 + 27%; R 300 + 58%; p less than 0.01). All three drug regimens caused similar significant decreases of nocturnal acidity (N 150-72%; N 300-79%; R 300-85%; p less than 0.01) and increases of nocturnal plasma gastrin concentration (N 150 + 41%; N300 + 52%; R 300 + 80%; p less than 0.01). Dosing with ranitidine 300 mg at 21:00 h also caused a simultaneous significant decrease of morning acidity (-32%; p less than 0.05) with a significant increase of plasma gastrin concentration (+36%; p less than 0.05), but the antisecretory effects of nizatidine 150 or 300 mg at 21:00 h were only observed during the night, with no effect during the morning. No drug regimen had any effect on acidity or plasma gastrin in the afternoon or early evening.

RCT Entities:   Population Interventions Outcomes