[On the pharmacokinetics of spironolactone in the elderly]

The pharmacokinetics of canrenone were compared in 10 elderly (77.2 years) patients and 10 young (20.1 years) female persons after multiple oral dosing of 100 mg Spironolactone during steady-state. The concentrations were determined using both a specific HPLC-assay and a nonspecific fluorometric assay. Maximum as well as mean concentrations of canrenone in serum of the elderly subjects were approximately twice as high as those in the young. This was the consequence of an impaired capacity for elimination of spironolactone in the elderly subject. In addition the ratio of the other fluorigenic metabolites and of canrenone were higher in the elderly. Thus also shifts in the metabolic pathways of spironolactone occur with progressing age.