Potassium supplements and total body potassium in elderly patients

Total body potassium (TBK) and serum potassium measurements have been obtained in nine elderly patients in controlled heart failure on differing diuretic regimens. The patients were randomly maintained on a potassium-sparing diuretic, on frusemide, and on frusemide with potassium supplements (48 mmol/day) for a minimum of one month. TBK levels increased by a mean of 128 mmol on frusemide with potassium supplements compared with no supplements (P less than 0.001), a 7% increase in TBK. Serum potassium levels increased, similarly, from 4.1 mmol/l to 4.8 mmol/l (P less than 0.01). The potassium-sparing diuretic had the same effect as frusemide with supplements in increasing TBK in six patients. However, in three cases there was no increase in TBK compared with frusemide alone. The results demonstrate that potassium supplements are effective in raising TBK levels and serum potassium levels in elderly patients with heart failure.