SUPERIMPOSITION OF 24-HOUR BLOOD-PRESSURE PROFILES DURING LONG-TERM TREATMENT WITH ISRADIPINE SRO

The long-term reproducibility of blood pressure (BP) variability was e valuated in an open-label study of patients with mild to moderate hype rtension controlled by the calcium antagonist isradipine. Thirty-one p atients, 18 men and 13 women, were treated with isradipine 5 mg in a s ustained-release formulation (SRO). Twenty-four-hour ambulatory BP rec ordings were taken at baseline and at 6, 26, and 52 weeks. At the 6-we ek follow-up, mean BP was significantly reduced: from 141/88 mm Hg to 129/81 mm Hg in men and from 144/92 mm Hg to 129/83 mm Hg in women; fe w changes were observed in subsequent months. Other parameters evaluat ed were amplitudes attributable to the first two harmonics, which did not change over time. The third variable investigated angular and circ ular means of the phases (expressed in hours and minutes); the fourth parameter, the rate at which BP changed within the linear intervals, w as generally lower in men than in women during the nocturnal BP decrea se; no differences were observed between sexes around the time of awak ening. Interestingly, an inverse relationship applied to the rate and the length of the interval for both diastolic and systolic BP in men a nd women; ie, when the rate increased, the length decreased, and vice versa. All characteristics of the BP profile were similar at the 6-, 2 6-, and 52-week evaluation. After an anticipated reduction in mean BP following the start of treatment, isradipine SRO reduced daily BP valu es in both men and women, thereby ensuring a physiologic circadian rhy thm. This beneficial effect was maintained after 52 weeks of treatment .