Are calcium antagonists helpful in the management of primary aldosteronism?

The chronic effect of the calcium antagonist nitrendipine, a 1,4-dihydropyridine derivative, on blood pressure (BP), plasma aldosterone concentration (PAC), plasma renin activity (PRA), and serum potassium was investigated in six patients with primary aldosteronism, either due to an (unilateral) aldosterone-producing adenoma (APA) (n = 3; age 44 +/- 4 years; PAC: 312 +/- 96 pg/ml; PRA: less than 0.1 ng/L/h; serum potassium: 2.8 +/- 0.3 mmol/L) or to bilateral idiopathic hyperaldosteronism (IHA): (n = 3; age 49 +/- 1 years; PAC: 212 +/- 32 pg/ml; PRA: 0.1 +/- 0.1 ng/L/h; serum potassium: 3.3 +/- 0.2 mmol/L). After withdrawal of antihypertensive medications 2 weeks prior to the study, nitrendipine was given orally in a daily dosage of 40-60 mg. BP, PAC, PRA, and serum potassium were determined before and after 4 weeks of nitrendipine therapy. After 4 weeks, blood pressure was significantly reduced (178 +/- 10 to 165 +/- 6 mm Hg systolic, 109 +/- 7 to 101 +/- 6 mm Hg diastolic) in three patients with APA and in two with IHA. No significant changes of PAC, PRA, and serum potassium were observed in these patients. However, one patient with clinical characteristics of IHA and a long-term history of diuretic therapy showed a complete normalization of BP, PAC, PRA, and serum potassium, suggesting that the etiology of autonomous hyperaldosteronism in this patient might differ from typical primary aldosteronism. From these findings, we follow that calcium antagonists do not normalize BP, PAC, PRA, and serum potassium in patients with APA.(ABSTRACT TRUNCATED AT 250 WORDS)