Amlodipine versus diltiazem controlled release as monotherapy in patients with stable coronary artery disease

Abstract

This study was designed to compare the efficacy and tolerability of amlodipine (5 or 10 mg once daily [QD]) and diltiazem controlled release (CR) (90 or 120 mg twice daily [BID]) as monotherapy in reducing exercise-induced myocardial ischemia. This 8-week, parallel-group, randomized, double-masked study involved 132 patients at 10 outpatient cardiology centers. Patients had proven coronary artery disease confirmed by a typical history of stable angina pectoris, a positive exercise tolerance test, and a positive thallium scan or coronary angiogram. The main outcome measure was a bicycle exercise tolerance test. Median times to 1-mm ST-segment depression increased significantly (16%) for patients in both the amlodipine and diltiazem CR treatment groups. The time to onset of chest discomfort increased significantly after 4 and 8 weeks of treatment by 10% and 12% for amlodipine and by 5% and 7% for diltiazem CR, respectively. Amlodipine also showed a significant increase in median time until end of exercise (5%). However, the difference between treatments was not significant and no between-group differences were noted in anginal attack rates or nitroglycerin consumption. Amlodipine was withdrawn in 3% of patients and diltiazem CR in 9% because of adverse events. Adverse events were reported by 15% of amlodipine-treated patients and 26% of diltiazem CR-treated patients. Although the differences were not statistically significant, there was a trend toward an improved efficacy and safety profile with amlodipine 5 or 10 mg QD compared with diltiazem CR 90 or 120 mg BID in patients with exercise-induced myocardial ischemia.