title: Reduction of gastric acidity with ranitidine or famotidine: early evening dosage is more effective than late evening dosage.
abstract: The antisecretory effect of a once daily dose of ranitidine and famotidine was examined after administration of the drugs either immediately after dinner or 3 h after dinner. A placebo-controlled multiple cross-over study was performed in 7 healthy ambulatory volunteers. They were given, on 6 separate days at least 1 week apart, either placebo, ranitidine 300 mg or famotidine 40 mg, either immediately after dinner or 3 h later. Breakfast, lunch and dinner were standardized. 24-Hour intragastric acidity was measured with a combined glass electrode. Duration of secretory inhibition by a drug was defined as the nighttime period between the first rise of pH above and the final fall below 3.5. This value represents the 95% upper confidence limit of nighttime pH values during placebo treatment. Secretory inhibition with early and late administration of ranitidine lasted for 10.7 and 7.3 h, respectively (p = 0.012). With famotidine it lasted for 10.1 and 7.1 h, respectively (p = 0.005). Gastric acidity after dinner was decreased by early but not late intake of ranitidine and famotidine. Thus, both ranitidine and famotidine were more effective when taken early, immediately after dinner, than when taken late in the evening. This observation might affect the mode of ulcer treatment with these drugs.
mesh_terms: D000328:Adult; D004334:Drug Administration Schedule; D015738:Famotidine; D005260:Female; D005744:Gastric Acid / Q000378:metabolism*; D005745:Gastric Acidity Determination; D006635:Histamine H2 Antagonists / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D011899:Ranitidine / Q000008:administration & dosage*; D013844:Thiazoles / Q000008:administration & dosage*
chemical_list: D006635:Histamine H2 Antagonists; D013844:Thiazoles; D015738:Famotidine; D011899:Ranitidine