Antihypertensive effects and pharmacokinetics of felodipine combined with a beta-blocker and a diuretic.

The antihypertensive effect of felodipine, a new calcium antagonist with dihydropyridine structure, was investigated in 25 patients with essential hypertension that was not controlled on standard triple therapy (a beta-blocker, a diuretic, and a vasodilator). After substituting the previous vasodilator with felodipine, blood pressure was reduced and remained well controlled during a 2 year follow-up period. After about 1 1/2 years of treatment, felodipine was compared double-blind with placebo in a subgroup of 10 patients while keeping the same beta-blocker and diuretic therapy. Compared with the placebo, felodipine lowered blood pressure during a 12 h interval, which supports a twice-daily dosage in clinical practice. Determination of the plasma concentrations of felodipine during steady-state conditions showed a mean elimination half-life of 23.4 +/- 11.1 h. During long-term therapy, tolerance was good, and felodipine seems to be a safe and efficient antihypertensive agent in combination with a beta-blocker and a diuretic in patients whose hypertension is not adequately controlled on standard triple therapy.