Interference by ranitidine with aldosterone secretion in vivo.

The effect of a 3-day oral course of ranitidine on plasma aldosterone level has been studied in 6 normotensive volunteers maintained in a state of sodium depletion. A significant fall in plasma aldosterone (p less than 0.05-0.02), in both the overnight recumbency levels and in the levels obtained during a two hour period of ambulation was observed. The change took place in the absence of variation in plasma renin activity and potassium. Plasma cortisol and prolactin levels were lower after ranitidine at the beginning of the test but their values were not significantly different after ambulation during ranitidine therapy. Ranitidine appears to interfere with aldosterone secretion in vivo.