Alternative medical treatment for patients with angina pectoris and adverse reactions to beta blockers. Usefulness of nifedipine.

Although beta blockers are effective for the treatment of angina pectoris, chronic adverse effects produced by these agents--including lethargy, fatigue, and male impotence--can adversely affect patient acceptance and treatment compliance. To assess the clinical effects of switching from anti-anginal treatment with beta blocker only (phase I) to half-dose beta blocker plus the calcium blocker nifedipine (phase II) or nifedipine alone (phase III), 18 patients with chronic stable angina pectoris and side effects to beta blockers were evaluated in a 12-week, open-label trial. Three patients did not complete the study, one secondary to new unstable angina and two secondary to nifedipine side effects. Of the 15 patients completing the trial (13 men and two women; mean age, 54 +/- 5 [SEM] years), all sequentially participated in the one-month phases. Weekly angina frequency assessed from patient diaries was significantly less for treatment with nifedipine only (phase III) as compared with beta blocker (phase I) (1.7 +/- 1 versus 3.9 +/- 1 episodes per week), while phase II was not significantly different. Exercise test time was maintained throughout all phases (phase I, 457 +/- 39; phase II, 458 +/- 40; and phase III, 498 +/- 48 seconds, p not significant). All 15 patients in phase I (100 percent) had side effects to beta blockers, but these side effects were lessened in 12 patients (80 percent) in phase II and 13 patients (86 percent) in phase III, with total alleviation of symptoms in two patients (13 percent) in phase II, and eight patients (53 percent) in phase III. Thus, in patients with side effects to beta blockers, switching to nifedipine is associated with a significant reduction in beta blocker adverse symptoms and equal anti-anginal efficacy.