Low-dose and very low-dose spironolactone in combination therapy for essential hypertension: evaluation by self-measurement of blood pressure at home.

Low-dose (25 mg) or very low-dose (12.5 mg) spironolactone were added among 86 uncontrolled hypertensive patients who were undergoing monotherapy with calcium channel blockers (CCBs), angiotensin-converting enzyme inhibitors (ACEIs), or angiotensin AT1-receptor blockers (ARBs). Morning home systolic/diastolic blood pressure (BP) reduction was similar among the CCB (n = 30, -8.2/-2.6 mmHg), ACEI (n = 22, -13.0/-4.7 mmHg), and ARB (n = 34, -11.5/-5.1 mmHg) groups. An increase in serum potassium correlated positively with the decline in morning systolic BP. Even very low-dose (12.5 mg) spironolactone is clinically effective, although serum potassium should be carefully monitored.