Nonselective Beta-adrenergic blockade augments fasting hyperkalemia in hemodialysis patients.
OBJECTIVE
Fasting hyperkalemia in patients with end-stage renal failure is a well-documented phenomenon. Both a decreased secretion of insulin and decreased beta-adrenergic receptor sensitivity may take part in this effect.


METHODS
Twelve anuric, long-term (6.4 +/- 2.7 years; mean +/- SD) hemodialysis patients underwent three periods of 18-hour fasting (from 6 p.m. to 12 a.m.). At the beginning of each fasting period a single dose of the nonselective beta-blocker, nadolol (80 mg), or the beta(1)-selective blocker, betaxolol (20 mg), or placebo were given in a random order and in blinded fashion. The wash-out period was 7 days.


RESULTS
The mean decrease in blood pressure was similar after nadolol and betaxolol (18 +/- 10 vs. 19 +/- 11 mm Hg) as was a decrease in heart rate (20 +/- 3 and 19 +/- 6, respectively). Serum potassium was not different before each of the fasting periods. The increase in serum potassium during fasting was highly significant in each case. The mean increase in serum potassium was 1.2 +/- 0.4 mmol/l after nadolol, 0.9 +/- 0.6 after betaxolol and 0.6 +/- 0.6 after placebo. This effect was significantly larger after nadolol than after placebo (p = 0.01), but this relation was not significant with respect to betaxolol (p = 0.30). Serum insulin as well as glucose decreased significantly and to a similar extent during each fasting period. Plasma aldosterone was unchanged.


CONCLUSIONS
Nonselective beta-adrenergic blockade increases the hyperkalemic effect of fasting in hemodialysis patients.
Nowicki
Michał
M
Department of Nephrology, Polish Mother's Memorial Hospital Research Institute, Łódź, Poland. nefro@wp.pl
Miszczak-Kuban
Joanna
J
D000319:Adrenergic beta-Antagonists / Q000009:adverse effects*; D000328:Adult; D000450:Aldosterone / Q000097:blood; D001786:Blood Glucose; D001794:Blood Pressure; D005215:Fasting; D005260:Female; D006801:Humans; D006947:Hyperkalemia / Q000139:chemically induced* / Q000209:etiology*; D006977:Hypertension, Renal / Q000188:drug therapy; D007676:Kidney Failure, Chronic / Q000097:blood / Q000150:complications* / Q000628:therapy; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000097:blood; D006435:Renal Dialysis; D012964:Sodium / Q000097:blood
D000319:Adrenergic beta-Antagonists; D001786:Blood Glucose; D000450:Aldosterone; D012964:Sodium; D011188:Potassium