Clinical effects of eplerenone, a selective aldosterone blocker, in Japanese patients with essential hypertension.

Eplerenone, a selective aldosterone blocker, has become clinically available in Japan since 2007. It has been reported that eplerenone has a potential antihypertensive effect, with a profile slightly different from that of spironolactone, and has fewer adverse reactions, suggesting that it may become a first-line treatment for hypertension. However, clinical data on hypertensive patients in Japan are lacking for eplerenone. In this study, we explored the clinical efficacy of eplerenone when it is added to an angiotensin-converting enzyme (ACE) inhibitor or a long-acting calcium channel blocker (CCB) in 68 (31 males, 37 females) Japanese patients with essential hypertension. After adding 50 mg of eplerenone to their basal treatment, blood pressure was significantly reduced at 4 weeks, and further reduced after 24 weeks of eplerenone treatment. Urinary albumin excretion decreased significantly after 24 weeks. There were no significant differences in general biochemical test values or electrolytes, but fasting serum triglycerides were significantly decreased after eplerenone treatment. The serum potassium level showed no significant change during treatment. There were no significant correlations between plasma renin activity or plasma aldosterone concentration (PAC) before eplerenone treatment and blood pressure after eplerenone treatment, showing that the antihypertensive effect of eplerenone is not affected by the patient's renin profile or pretreatment PAC values. Eplerenone was also effective in hypertensive patients with metabolic syndrome. In conclusion, eplerenone, when coadministered with an ACE inhibitor or a long-acting CCB, caused an extremely beneficial antihypertensive effect in Japanese patients with essential hypertension, without few clinically important adverse events.