Digoxin concentration in choroid plexus, brain, and myocardium in old age.

Thirteen aged persons receiving digoxin until the time of death were examined by autopsy, and digoxin concentrations were determined in samples from various tissues (the choroid plexus, grey and white brain matter, left and right ventricular and left and atrial myocardium, diaphragm, and musculus psoas major). These concentrations were related to the digoxin dose and duration of treatment. No significant difference was found between the concentration of digoxin in the choroid plexus and left ventricular myocardium, whereas there were significantly lower concentrations in the right ventricular myocardium and still lower concentrations in the other tissues analyzed. Independent of the digoxin dose, the digoxin concentrations in the choroid plexus tended to be lower in persons treated for a short time before death than in those treated for longer periods of time. Similar differences were not observed in the other tissues, suggesting a slower rate of digoxin uptake in the chroid plexus compared with the myocardium and other tissues. The implications of these findings for the effects of digoxin treatment on the production of cerebrospinal fluid are discussed.