Metabolic Studies, Aldosterone Secretion Rate, and Plasma Renin after Carbenoxolone Sodium

A formal metabolic study of carbenoxolone sodium (Biogastrone) 300 mg./day has been performed for 17 days on a woman with gastric ulcer who in a previous 21-day trial, on a 52-mEq sodium diet, showed weight gain, retention, and rise in plasma sodium and chloride concentrations, as well as hypokalaemia without change in potassium balance. In the present trial sodium intake was restricted to 26 mEq/day; while plasma electrolyte changes of lesser degree still occurred, there was no retention of water, sodium, or chloride. Aldosterone secretion in the control period was 202 μg./24 hours, and fell to 74 μg./24 hours after carbenoxolone, but plasma renin was unchanged. These results suggest that the mineralocorticoid effects of carbenoxolone (and presumably of liquorice and its other derivatives) are due to an intrinsic aldosterone-like action, and that, with sodium deprivation, aldosterone secretion is suppressed by a mechanism which is not renin-mediated—possibly hypokalaemia.