The elimination half-life (T1/2) of canrenone, the principal unconjugated metabolite of spironolactone, was 59 h (range 32–105 h) in 5 patients with chronic liver disease and 37 h (range 19–48 h) in 7 patients with congestive heart failure. In comparison the T1/2 in normal subjects was 13.5–24 h in previous reports and 20.5 h in the present study. However there was no evidence of greater cumulation of canrenone in the plasma of those patients with a prolonged T1/2.
Key words Spironolactone - canrenone - half-life - cardiac failure - cirrhosis - aldosterone antagonist