Once daily felodipine in preventing ergonovine-induced myocardial ischaemia in Prinzmetal's variant angina

Abstract

The efficacy of extended-release felodipine in preventing ergonovine-induced myocardial ischaemia was assessed in 14 patients (12 male, two female, aged 56 +/- 7 years) with Prinzmetal's variant angina. Four of the patients had normal coronary arteries, eight had one-vessel and two had two-vessel disease. The ergonovine test was performed once in basal conditions and twice 5 days after beginning the oral administration of felodipine 20 mg o.d., 4 and 24 h after the last administration. During a continuous 6-lead ECG recording, ergonovine was injected at doses of 25, 50, 100, 200, and 400 micrograms at 5 min intervals. Blood samples for felodipine plasma concentrations were drawn at the time of the tests. The basal ergonovine test was positive in all 14 patients (seven with anterior and seven with inferior ST segment elevation > 0.1 mV) at a mean ergonovine dose of 162 +/- 138 micrograms. The test was repeated 4 h after the last felodipine administration and was negative in 13 patients (93%), but 24 h after the last drug administration, eight patients (57%) had a positive test response (five with anterior, three with inferior ST segment elevation) at a higher ergonovine dose than at baseline (150 vs 97 micrograms, P = 0.042). The only differences between patients with a negative and a positive test were the mean values of the left ventricular end-diastolic pressure (9.3 vs 14.9 mmHg, P = 0.002) and the ergonovine doses used in the baseline tests (250 vs 97 micrograms, P = 0.034).(ABSTRACT TRUNCATED AT 250 WORDS)