Antihypertensive effects of felodipine compared with placebo.

The effects of felodipine and placebo on blood pressure, heart rate and tolerability were investigated in 4 different groups of patients. One group had not received previous therapy, whereas the other 3 groups received concomitant antihypertensive compounds (beta-blockers, diuretics or beta-blocker + diuretics). The haemodynamic effects and tolerability were studied after a single dose, as well as during steady-state conditions. After a single dose of felodipine there was a rapid and significant decrease in blood pressure and increase in heart rate with felodipine alone as well as with combination therapy. During long term treatment, blood pressure was significantly decreased after felodipine during the dosing interval (12h), irrespective of concomitant treatment. Heart rate, however, was not increased, even in patients without a beta-blocker. The reduction in blood pressure was correlated with the plasma concentration of felodipine after single-dose administration, but not during long term treatment. Felodipine was generally well tolerated. In the short term, headache was the most common side effect, while swelling of the ankles was the most frequent adverse effect during long term treatment. In conclusion, felodipine is a promising antihypertensive compound, which may be used in the treatment of high blood pressure, either alone or in combination with other agents.