Summary
Amlodipine, a dihydropyrimidine calcium antagonist, is effective in the treatment of patients with mild to moderate hypertension at doses of 5–10 mg daily. The aim of the study reported here was to determine whether an early increase in dosage of amlodipine provided an advantage in terms of antihypertensive effect. This was a single-blind, randomised study in 115 patients with mild to moderate hypertension (diastolic blood pressure 95–114mmHg) conducted at 10 centres with two parallel groups. Group I received amlodipine 5mg once daily for the entire 10-week treatment period, while group II received amlodipine 5 mg once daily for two weeks, with the option to increase the dose to 10 mg once daily were the diastolic blood pressure to exceed 90 mmHg. The dose was increased in 40% of group 11 patients (20/50). Diastolic and systolic blood pressure decreased steadily until the end of the sixth week of treatment in both groups, with no statistically significant difference between the groups. The response rate (diastolic blood pressure ≤ 90 mmHg) at the end of treatment was 84% in both groups. Because there is no advantage in an early increase in dosage of amlodipine in terms of antihypertensive effect, a dose increase should not be considered until after six weeks of treatment at 5 mg once daily.