Comparison of monotherapy with irbesartan 150 mg or amlodipine 5 mg for treatment of mild-to-moderate hypertension.
OBJECTIVE
The primary objective of this study was to compare the antihypertensive efficacy of the angiotensin II receptor blocker irbesartan 150 mg and the calcium channel blocker amlodipine 5 mg in the treatment of patients with seated diastolic blood pressure (DBP) 95-110 mmHg.


METHODS
Multicentre, randomised, double-blind, comparative pilot study.


METHODS
Subjects were 18-65 years of age, with DBP 95-110 mmHg, and of non-African American origin. Following a three week, single-blind, placebo lead-in period, 181 subjects were randomised in a 1:1 ratio to receive once-daily irbesartan 150 mg (n=89) or amlodipine 5 mg (n=92) for four weeks. Trough (24+/-3 hours post-dosing) BP measurements were obtained at baseline and at Weeks 2 and 4 under standardised, controlled conditions. Response was defined as DBP <90 mmHg or a reduction from baseline of 10 mmHg.


RESULTS
After four weeks of treatment, the mean (+/-SE) decrease from baseline in DBP was 9.4+/-0.6 mmHg in the irbesartan group vs. 9.6+/-0.6 mmHg in the amlodipine group (p=0.806). The mean decrease from baseline in seated systolic BP was 12.2+/-1.0 mmHg in the irbesartan group vs. 12.0+/-1.0 mmHg in the amlodipine group (p=0.885). Overall, 62% of subjects in the irbesartan group and 63% in the amlodipine group had a response (p=0.609), and 54% and 56% of patients (p=0.596), respectively, had their DBP normalised (<90 mmHg). Adverse events were reported by 21.3% of patients receiving irbesartan and 20.7% receiving amlodipine. Conclusions. Irbesartan 150 mg demonstrated comparable efficacy to amlodipine 5 mg, thereby confirming its value as an antihypertensive treatment option in non-African American patients with DBP 95-110 mmHg.
Orange County Research Center, Tustin, CA 92780, USA. jmneutel@aol.com
Joel M
JM
Neutel
F Wilford
FW
Germino
David
D
Smith
D000293:Adolescent; D000328:Adult; D000368:Aged; D017311:Amlodipine / Q000009:adverse effects / Q000627:therapeutic use*; D047228:Angiotensin II Type 1 Receptor Blockers / Q000009:adverse effects / Q000627:therapeutic use*; D000959:Antihypertensive Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001713:Biphenyl Compounds / Q000009:adverse effects / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000009:adverse effects / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D000077405:Irbesartan; D008297:Male; D008875:Middle Aged; D013777:Tetrazoles / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome
D047228:Angiotensin II Type 1 Receptor Blockers; D000959:Antihypertensive Agents; D001713:Biphenyl Compounds; D002121:Calcium Channel Blockers; D013777:Tetrazoles; D017311:Amlodipine; D000077405:Irbesartan