Enhancement by food of canrenone bioavailability from spironolactone

The influence of food intake on the bioavailability of canrenone, the major and active metabolite of spironolactone, was explored in 8 healthy male volunteers. Spironolactone was administered as a single oral dose of 100 mg, both in the fasting state and together with a standardized breakfast. Numerous venous blood samples were taken from 30 min to 96 hr after ingestion of the drug, and the plasma concentrations of canrenone were determined by spectrofluorometry. The results indicate that more canrenone enters the general circulation when spironolactone in ingested together with a meal.