Treatment of essential hypertension with felodipine in combination with a diuretic.

In a double-blind cross-over study, the effect on blood pressure (BP), heart rate (HR) and plasma noradrenaline concentration (pNA) of placebo or felodipine given in addition to hydrochlorothiazide was studied in 12 male patients with essential hypertension, not satisfactorily controlled with the diuretic alone. The first dose of felodipine decreased BP and increased HR for about 6 h. After 4 weeks of treatment with felodipine, BP was reduced for 24 h, whereas HR was only transiently increased. The elimination half-life of felodipine was about 23 h. The plasma noradrenaline concentration increased after felodipine and serum uric acid decreased. Side-effects were few and usually mild.