Prospective direct comparison of antihypertensive effect and safety between high-dose amlodipine or indapamide in hypertensive patients uncontrolled by standard doses of angiotensin receptor blockers and amlodipine.
OBJECTIVE
When hypertension is uncontrolled by routine treatment with an angiotensin II receptor blocker (ARB) and the calcium channel blocker amlodipine (5 mg), the dose of amlodipine can be increased or a diuretic can be added. We investigated the more effective option in a prospective multicenter open-label study.


METHODS
Hypertensive patients were recruited if the target blood pressure (BP) in The Japanese Society of Hypertension 2009 guideline could not be achieved with standard-dose ARB therapy and amlodipine (5 mg).


PATIENTS
Patients were divided into three groups. Group-1 was switched to a combination of irbesartan (100 mg) and amlodipine (10 mg). Group-2A was changed to a combination of irbesartan (100 mg), amlodipine (5 mg), and indapamide, while Group-2B received a standard-dose ARB and amlodipine (5 mg) plus indapamide. Patients were assigned by their attending physicians and were followed for 6 months. The primary endpoint was the antihypertensive effect of each regimen.


RESULTS
Group-1 contained 85 patients, Group-2A had 49 patients, and Group-2B had 4 patients. We only analyzed Group-1 and Group-2A due to the small size of Group-2B. In both groups, systolic BP and diastolic BP were significantly decreased up to 6 months (all p < 0.001). Reduction of systolic BP was greater in Group-1 than Group-2A after 1 month and 6 months (both p < 0.05). Uric acid was increased in Group-2A after 3 months, but not at 6 months.


CONCLUSION
Although both regimens were effective for reducing BP, increasing amlodipine to 10 mg daily controlled hypertension without elevation of serum uric acid.
['Okamura|Keisuke|K|', 'Shirai|Kazuyuki|K|', 'Totake|Nao|N|', 'Okuda|Tetsu|T|', 'Urata|Hidenori|H|']
D000368:Aged D000369:Aged, 80 and over D017311:Amlodipine D057911:Angiotensin Receptor Antagonists D000959:Antihypertensive Agents D001713:Biphenyl Compounds D001794:Blood Pressure D004359:Drug Therapy, Combination D005260:Female D006801:Humans D006973:Hypertension D007190:Indapamide D000077405:Irbesartan D008297:Male D008875:Middle Aged D011446:Prospective Studies D013777:Tetrazoles D016896:Treatment Outcome D014527:Uric Acid
hypertension Angiotensin II receptor blocker calcium channel blocker combination drug multicenter study