title: Effects of ranitidine 150 mg four times a day on 24-hour intragastric acidity and 24-hour plasma gastrin concentration.
abstract: Twenty-four-hour integrated intragastric acidity and 24-hr integrated plasma gastrin concentration was measured twice in 23 healthy male volunteers on the seventh day of oral dosing with placebo or ranitidine 150 mg four times a day. The study was a randomized, double-blind, placebo-controlled, two-way crossover investigation. The mean integrated 24-hr intragastric acidity during dosing with ranitidine 150 mg four times a day decreased to 32% of the placebo value (placebo 825 mmol/hr/liter; ranitidine 265 mmol/hr/liter). The mean integrated 24-hr plasma gastrin concentration during dosing with ranitidine 150 mg four times a day was 904 pmol/hr/liter compared with placebo (410 pmol/hr/liter)--an increase of 122%. The median number of hours of pH > 3 during dosing with placebo and with ranitidine 150 mg four times a day were 5 and 11 hr, respectively. Ranitidine 150 mg four times a day caused a significant decrease of mean integrated intragastric acidity for each meal-related interval and also during the night.
authors.affiliation: University Department of Medicine, Royal Free Hospital School of Medicine, London, UK.
authors.forename: A G
authors.initials: AG
authors.lastname: Fraser
authors.forename: A M
authors.initials: AM
authors.lastname: Sawyerr
authors.forename: M
authors.initials: M
authors.lastname: Hudson
authors.forename: M
authors.initials: M
authors.lastname: Smith
authors.forename: R E
authors.initials: RE
authors.lastname: Pounder
mesh_terms: D000328:Adult; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004942:Esophagitis, Peptic / Q000188:drug therapy; D005744:Gastric Acid / Q000378:metabolism*; D005745:Gastric Acidity Determination; D005755:Gastrins / Q000097:blood*; D006801:Humans; D008297:Male; D011899:Ranitidine / Q000008:administration & dosage* / Q000494:pharmacology*
chemical_list: D005755:Gastrins; D011899:Ranitidine