Haemodynamic effects of intravenous felodipine in normotensive and hypertensive subjects.

The effects of intravenous administration of a new calcium antagonist, felodipine, were studied in healthy subjects and hypertensive patients. Felodipine infused at a rate of 0.01 mg/min in 10 normotensive volunteers caused gradual haemodynamic and hormonal changes compatible with a direct vasodilatory mechanism of action; it also had a diuretic and natriuretic effect. When infused at a mean dose of 0.02 mg/kg bodyweight over 20 to 120 minutes in 7 patients with a hypertensive emergency, felodipine caused a rapid reduction in blood pressure with a maximal fall in mean arterial pressure of 30.4 +/- 7.3% (mean +/- 1 SD) in 30 minutes. No serious side effects were observed. The haemodynamic effectiveness of an infusion rate of 0.01 mg/min was confirmed in a pilot study of 5 patients with refractory hypertension. On the basis of these findings, a schedule for the treatment of acute hypertension with intravenous felodipine is proposed.