Assessment on antihypertensive effect and safety of nifedipine controlled-release tablet administered at 80 mg/day in practical clinic.

In this study, the effect of nifedipine controlled-release tablets at a dose of 80 mg/day (NCR80) on blood pressure (BP) and safety was investigated. In essential hypertension (n = 50, >140/90 mm Hg) despite a combined therapy with antihypertensive agents, NCR80 was administered instead of the previous antihypertensive agents and changes in BP and pulse rate (PR), side effects, and changes in laboratory test values were examined for 24 months. Thirty-three patients switched to NCR80 as the initial dose from the previous antihypertensive agents (Initial), while 17 patients started treatment at NCR40 and increased to NCR80 after 1-3 months (Up-titration). In the Initial group, BP decreased significantly and this significant reduction continued for 24 months, but not in the case of PR. In the Up-titration group, BP decreased significantly during the treatment with NCR40, and further reduced in 1-2 month(s) after NCR80. This significant reduction continued for 12 months, but not in the case of PR. The mean change in BP after increasing NCR40 to NCR80 was -16/-6 mm Hg at 6 months. When patients who received NCR80 were stratified into three grades according to the baseline systolic blood pressure level (SBP) (≥180, 160-179, and 140-159 mm Hg), the mean change in BP at 1 month was -55, -27, and -16 mm Hg, respectively. None of the 50 patients treated with NCR80 experienced any side effects and no abnormal change was observed in their laboratory test values. These findings suggested that NCR80 demonstrated the ability to control BP appropriately depending on the severity with favorable safety.