Losartan/Hydrochlorothiazide Fixed Combination Versus Amlodipine Monotherapy in Korean Patients With Mild to Moderate Hypertension

BACKGROUND AND OBJECTIVES: The antihypertensive efficacy and tolerability of losartan (LST) in fixed combination with hydrochlorothiazide (HCTZ) has not been compared to those of amlodipine monotherapy in Asians. This is an important comparison to draw, because Asians have been suggested to respond more favorably to calcium channel blockers and less favorably to angiotensin-converting enzyme inhibitors in comparison to Westerners. We sought to compare these two regimens in Korean patients with mild to moderate hypertension. SUBJECTS AND METHODS: 174 patients were randomized to receive LST 50 mg once daily, which could be titrated to LST/HCTZ 50/12.5 mg at 4 weeks, followed by 100/25 mg at 8 weeks; or to receive amlodipine besylate 2.5 mg once daily, which could be titrated to 5 mg at 4 weeks, followed by 10 mg at 8 weeks to achieve diastolic blood pressure <90 mmHg. RESULTS: At 12 weeks, the differences between the LST/HCTZ and amlodipine groups with regard to diastolic and systolic blood pressure were 1.2 mmHg (95% confidence interval: -1.1 to 3.4) and -0.5 mmHg (95% confidence interval: -4.3 to 3.4), respectively. The rates of achieving systolic blood pressure <140 mmHg were 66.7% in the LST/HCTZ group and 75.9% in the amlodipine group (p=0.20). The rates of drug-related adverse events were 15.6% in the LST/HCTZ group and 11.9% in the amlodipine group (p=0.49). CONCLUSION: The two regimens, with a relatively higher dose of LST/HCTZ compared to that required in Westerners, produced equivalent blood pressure reduction and were comparably well tolerated in Korean patients with mild to moderate hypertension.