Effect of a 28-day therapy with famotidine on blood levels of alcohol and gastrin and intragastric pH in healthy human subjects.

In a randomized, placebo-controlled study of 10 healthy human subjects blood alcohol levels after consumption of beer, 24-h intragastric pH, and serum gastrin concentrations were serially measured during a 28-day therapy with famotidine. The subjects consumed placebo or famotidine (40 mg at 1830 h) and beer (500 ml at 1900 h) every day for 28 days. On days 1, 7, and 28 of the study 24-h intragastric pH-metry and blood alcohol and gastrin estimations were performed. Famotidine did not significantly alter either the peak or the 2-h integrated blood alcohol response to beer. The median intragastric pH on days 1, 7, and 28 was significantly (p < 0.006) increased by famotidine. After 7 days of famotidine therapy, however, the pH was significantly (p < 0.03) lower than on day 1 (4.0 versus 2.4); this effect persisted on day 28 (2.3). Whereas basal plasma levels of gastrin were not significantly altered by famotidine, the 2-h integrated plasma gastrin response to beer was significantly (p < 0.05) higher with famotidine than with placebo. We conclude that 1) a 28-day therapy with famotidine does not alter blood alcohol levels in response to social consumption of beer; 2) after 7 days of therapy tolerance to its gastric acid-inhibitory effect is seen; and 3) an exaggerated postprandial release of gastrin may be involved in the development of this tolerance.