ABSTRACT
In 30 consecutive patients with Prinzmetal's angina pectoris, the antiischemic effect of felodipine, a new long-acting vasoselective calcium antagonist, administered at doses of 10 and 20 mg once daily was compared with that of the well-established therapeutic regimen with nifedipine administered at a dose of 20 mg 4 times daily. Twenty-four-hour Holter monitoring was performed during a 2-day placebo run-in and at the end of each of 3 consecutive 6-day periods during which the 3 active treatments were administered in randomized sequence. Three patients withdrew, whereas 27 completed the study. The therapeutic regimens tested proved to be similarly effective; primary end points (ischemic episodes recorded by Holter monitoring, and anginal attacks reported on diary cards) occurred in 5 patients (19%) during nifedipine treatment, and in 7 (26%) and 3 (11%) during felodipine treatment with 10 and 20 mg, respectively (p = not significant). The distribution of residual ischemic episodes demonstrated that treatment with felodipine once daily provides 24-hour antiischemic protection. Twenty-six patients were followed up with 20 mg of felodipine once daily for a mean of 6 +/- 5 months, and 21 of them (81%) remained free of symptoms and Holter-recorded ischemic attacks. It is concluded that for Prinzmetal's angina pectoris, 24-hour antiischemic protection may be achieved with administration of felodipine once daily. The availability of a simplified therapeutic approach may constitute a real advantage in terms of patient compliance and improving the quality of life.