Efficacy and safety of combination therapy with losartan and hydrochlorothiazide in elderly hypertension

Abstract

We examined the effect and safety of combination therapy with low-dose diuretics (hydrochlorothiazide: HCTZ) and angiotensin II receptor antagonist (losartan) in elderly cases of hypertension, using ambulatory blood pressure monitoring (ABPM). Elderly hypertensive patients (mean age 75 +/- 2 years) were treated with either losartan (25-50 mg/day) or HCTZ (12.5 mg/day) for at least 4 weeks, and then 24-hour blood pressure (BP) was measured by ABPM. Combination therapy with addition of other drug was initiated in 14 patients whose 24-hour systolic BP or daytime systolic BP was over 140 mmHg (160 mmHg for the patients of 80 years or older). After 4 weeks of the combination therapy, ABPM was repeated. Blood cell count and blood chemistry were also done before and after initiation of combination therapy. In the losartan-preceding group (n = 9), the combination therapy with HCTZ reduced 24-hour BP by 19.3 +/- 2.3/6.6 +/- 2.3 mmHg. Similarly, daytime and nighttime BP decreased by 21.4 +/- 4/8.4 +/- 2.8 mmHg and 15.2 +/- 4/4.2 +/- 2.4 mmHg, respectively. In the HCTZ-preceding group, the combination with losartan also decreased 24-hour BP by 12.2 +/- 4.8/3.4 +/- 1.4 mmHg. The decreases of daytime and nighttime BP were 13.8 +/- 6.6/4 +/- 1.1 mmHg and 10 +/- 4.7/3 +/- 2.4 mmHg, respectively. Heart rate did not change with combination therapy in the losartan-preceding group, while heart rate during daytime tended to decrease by addition of losartan in the HCTZ-preceding group (3.8 +/- 1.7/min). Serum electrolytes, uric acid, lipids, renal function and body weight did not change during the study period. Thus, combination therapy of losartan/hydrochlorothiazide seems useful in the treatment of elderly hypertension, showing additive BP lowering effect without metabolic adverse effects.