The effects of irbesartan added to hydrochlorothiazide for the treatment of hypertension in patients non-responsive to hydrochlorothiazide alone.
OBJECTIVE
To evaluate the antihypertensive efficacy and safety of adding irbesartan to hydrochloride (HCTZ) in patients not adequately controlled by HCTZ alone.


METHODS
In this multicenter study, after a single-blind, placebo lead-in period, hypertensive patients received single-blind HCTZ 25 mg once daily. After 4 weeks, 238 patients with seated diastolic blood pressure of 93-110 mmHg continued on HCTZ 25 mg once daily and were randomized to double-blind irbesartan 75 mg once daily or matching placebo for 12 weeks. At week 6, the dosage of irbesartan or placebo was doubled for seated diastolic blood pressure > or = 90 mmHg.


RESULTS
At weeks 2, 6, and 12, irbesartan/HCTZ resulted in significantly greater (P<0.01) reductions from baseline in trough seated diastolic and systolic blood pressure compared with placebo/HCTZ. At week 12, the mean reductions in trough seated diastolic and systolic blood pressure were 7.2 mmHg (95%, C.I., 5.1-9.3 mmHg) and 11.1 mmHg (95% C.I., 7.9-14.3 mmHg) greater, respectively, with irbesartan/HCTZ compared with placebo/HCTZ. At week 12, significantly (P < 0.01) more patients were normalized (trough seated diastolic blood pressure < 90 mmHg) with irbesartan/HCTZ (67%) compared with placebo/HCTZ (29%). The frequency of adverse events, serious adverse events, and discontinuations attributed to adverse events was similar in both groups, and there were no clinically relevant changes in serum creatinine, potassium, or any other laboratory parameter.


CONCLUSIONS
Irbesartan was effective and well tolerated when added to a background of HCTZ 25 mg in patients whose blood pressure was not adequately controlled by HCTZ alone.
Rosenstock
J
J
Dallas Diabetes and Endocrine Center, Texas 75230, USA.
Rossi
L
L
Lin
C S
CS
MacNeil
D
D
Osbakken
M
M
D000328:Adult; D000368:Aged; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D001713:Biphenyl Compounds / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects; D003710:Demography; D004359:Drug Therapy, Combination; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006852:Hydrochlorothiazide / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D006973:Hypertension / Q000188:drug therapy*; D000077405:Irbesartan; D008297:Male; D008875:Middle Aged; D016037:Single-Blind Method; D013777:Tetrazoles / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome
D000959:Antihypertensive Agents; D001713:Biphenyl Compounds; D013777:Tetrazoles; D006852:Hydrochlorothiazide; D000077405:Irbesartan