Comparison of Spironolactone and Amiloride on Home Blood Pressure in Resistant Hypertension

Inclusion Criteria: * Age 19-75 * Patients with resistant hypertension 1. 1st screening: ven while taking three or more types of antihypertensive medications including diuretics without changing the dose for 1 month, the average office systolic blood pressure measured in three times is 130-180 mmHg and daytime systolic blood pressure is ≥130 mmHg. 2. 2nd screening: An average systolic blood pressure of home blood pressure monitoring is ≥130 mmHg during the run-in period of antihypertensive drugs including diuretics (Sevikar HCT 5/20/12.5 mg, 5/40/12.5 mg or 10/40/12.5 mg). * Patients with resistant hypertension who have agreed to participate in the study: when they have the ability to write a written consent in accordance with the Korean Good Clinical Practice (KGCP) and local laws. * Patients who can change the currently used antihypertensive treatment to Sevikar HCT 5/20/12.5 mg, 5/40/12.5 mg or 10/40/12.5 mg without giving unacceptable risk (investigator's judgment) Exclusion Criteria: * White-coat uncontrolled hypertension * Severe hypertension (WHO classification criteria grade 3 average diastolic blood pressure ≥ 110 mmHg or average systolic blood pressure ≥ 180 mmHg) * Known cardiovascular disease (including stroke and TIA), including a history of angina, heart failure, myocardial infarction or revascularization, or cerebrovascular disease prior to 6 months * Congestive heart failure of III-IV according to NYHA functional classification * Clinically meaningful ventricular tachycardia, atrial fibrillation, atrial flutter, or other arrhythmia that the investigator has deemed clinically meaningful. * Hypertrophic obstructive cardiomyopathy, severe obstructive coronary artery disease, aortic stenosis, hemodynamically significant aortic valve or stenosis on the mitral valve * Renal insufficiency (basal estimated glomerular filtration rate (eGFR) \<50 ml / min / 1.73m2) * Hyperkalemia (\> 5.0 mmol / L, which can be reconfirmed if errors are suspected in the results) * Gastrointestinal diseases that can cause potential malabsorption the gastro-intestinal tract is severely narrowed; Kock pouch (a continent pouch formed by the terminal ileum after colectomy) * Bile stasis or biliary obstruction * liver disease or aspartate aminotransferase (AST) / alanine aminotransferase (ALT) levels \> 2-fold the normal upper limit (ULN) * Pregnant or fertile women who are not contraceptive or woman who are lactating * Intolerant to test drug/drug group or its components * Subjects who are currently participating in other clinical trials and who have taken other investigational product within the past month. * Subjects who have condition or a disease that may impede the completion of the test, according to the investigator's opinion * If assigned to treatment for this trial in the past * Uncorrected sodium or fluid depletion * History of drug or alcohol dependence within 6 months * The combination of medications known to affect blood pressure, except those permitted by the protocol. * Other clinical conditions that, as determined by the investigator, cannot be safely completed according to the protocol or that the investigational product cannot be safely used a history of secondary hypertension that cannot be corrected * Taking spironolactone or amiloride within 4 weeks from the time of screening * If discontinued due to side effects of spironolactone or amiloride