[Circadian antihypertensive effect of sustained-release isradipine in patients with essential hypertension in comparison to placebo].

In this multicenter, placebo-controlled study, 16 patients with mild to moderate essential hypertension were treated with 10 mg/day isradipine retard (PN 200-110, Lomir SRO, CAS 75695-93-1) for 3 weeks. The study started with a 2 week placebo wash out phase. 13 patients were randomised to an exclusive placebo therapy. After the placebo wash out phase, following the 1st medication in active therapy and after the end of therapy, 24-h blood pressure profiles were recorded. The profile under placebo on the 1st medication was separated by a one-week intervening placebo therapy for all patients. On active therapy, the systolic as well as the diastolic blood pressure (day time, night time and 24-h mean values) were significantly reduced. The antihypertensive effect of the active therapy became already manifest after the 1st medication and was augmented after 3 weeks of therapy. In the placebo group no parameter of the 24-h profiles changed significantly. The tolerability of treatment was excellent in 14 (87.5%) of the isradipine patients and in 10 (76.9%) of the placebo group. In one of 16 patients in the active group, adverse events (flush and ankle oedema) were observed. However, therapy could be continued. In one patient of the placebo group, oedema of the fingers was noticed, in another headache was documented. In the placebo group two patients discontinued the study due to inefficacy, in the isradipine group one patient for the same reason; a second patient was excluded from this group due to a concomitant disease unrelated to the study drug.